As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From the Paging Dr. Gupta blog, Terry asks:

"I would love some advice on choosing a heart rate monitor."

Answer:

Well, it turns out, Terry; our folks at CNN.com gave some great advice on this. Advice that I paid attention to since I’ve been working hard this year to get in better shape and am now training for a triathlon as a part of CNN’s Fit Nation Challenge.

As I train, something I've been focusing on is heart rate target training. It's actually pretty simple to do. First of all, calculate your maximum heart rate. The way that you do that, you subtract your age from the number 220. So, mine would be 180. Now, you calculate a range between 60 percent and 70 percent of that number. Mine would be from 108 to 126. Try and keep your pulse rate in that range while you work out. A heart rate monitor is a simple device to help you calculate your target heart rate and keep track of your workouts so you can measure your progress.

So Terry here is a rundown of heart rate monitors depending on what you’re looking for and how much you want to spend. There are a lot of monitors out there. New monitors are equipped with GPS, speed calculating shoe sensors and data analysis tracking every detail of your performance over time.

So, the experts CNN.com quoted said the new Garmin Forerunner 310XT is the optimal choice, but it is very expensive. It's almost $350. It does work anywhere in the world and you can get your heart rate, measure movement, elevation, distance and speed. Now, if you're looking for something more affordable, like a lot of people, Nike offers a slim watch size unit called the Nike Plus Sport Band. It runs about $59 and displays your distance, pace and calories burned. It holds about 30 hours worth of workout data. Check out more options at CNN.com/technology.

Keep in mind the longer your keep your body at that target heart rate I talked about, the more efficient your cardiovascular system will become, and overall, the fitter you will be. Good luck Terry hopefully tracking your heart rate will help you make your workouts even better.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Cyrus in Pittsburgh:

“Can obesity be linked to Alzheimer's disease? And can physical activity help ward off the disease?”

Answer:

There are two important questions here. The quick answer, of course, is yes. But obesity, as you might imagine, is just one part of the whole puzzle. First, most things that are bad for your heart are often bad for your brain as well. That’s one way to think about it. You see, it's all about blood flow. So what impedes or affects blood flow to the heart is generally going to cause the same in the brain. Elevated blood pressure, high triglycerides, and high cholesterol all affect blood flow and all increase your chances of developing Alzheimer's disease later in life.

The good news, to the second part of your question, is we know a lot about what we can do to prevent or delay the onset of this disease. Being physically active has been shown to improve mental function and to keep your brain healthier as you age. It's also essential for maintaining good blood flow and encouraging the growth of new brain cells. Studies show exercise that raises your heart rate for a minimum of 30 minutes several times a week seems to be the key. And exercise does so much more: It significantly reduces the risk of heart attack, stroke and diabetes. So stay active to keep your body and brain healthy for those later years.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

CNN blogger, Beata, asks:

"Of those who have lived long lives, what is the common thread? What's the one thing I can do today that can make me live longer?"

Answer:

For well over a decade I've been investigating the answer to this question. The good news is there are actually a lot of small lifestyle changes you can make today that will add years to your life. For instance, flossing can add a year to your life – a whole year – just by adding to your daily routine. Turns out there's a pretty clear link between gum disease and heart disease. Flossing is your best bet at stopping that.

Here are a few more: A low-dose aspirin a day could add two years, and limiting your coffee intake to two cups a day could add another year. Simply checking blood pressure regularly could add one and a half years, and exercising three times a week could add three years. Cut work hours down to a manageable 40-50 hours a week and you add another one and a half years. Add it all up – and you have added a decade of functional life.

I will be the first to admit, it isn't always easy to practice what I preach, especially when it comes to the work-hour issue. But, we do know stress affects just about every part of our bodies. Our bodies simply start to shut down and become unable to tolerate the assault being placed on them every day.

Earlier this week I sat down with anti-aging expert Dan Buettner. He explores the world searching for longevity hotspots, known as blue zones, and looks for the lessons we can learn from them. One thing Buettner points out is that the people who live long lives in blue zones around the world are stressed out too. Yet they are still living disease free and often to 100 years old. The difference is they don't internalize their stress as most of us do. They all practice simple techniques to de-stress including praying, napping, even happy hour. Also meditating, which I have started, for 20 minutes every day and taking time for yourself every day can help.

In case you missed it, click here to hear more of my conversation with the world's leading anti-aging experts and get more tips to live a longer, healthier life.

By Dr. Sanjay Gupta
Chief Medical Correspondent

This week we will be talking a lot about Afghanistan and the impact of the President’s speech. Having spent a fair amount of time there, including a trip just a couple of months ago, I am always reminded of the human impact of any conflict. I am reminded there are consequences to all those booms and explosions we see on television. I am reminded of the horrific injuries I saw due to IED explosions where young men and women are robbed of their legs, and their lives. I am also reminded of the remarkable sacrifice the doctors, nurses, medics and all the medical personnel make every single day out there. They truly risk their lives to save the lives of others.

Medicine and the military are embraced in an awkward dance and no where is that more true than in Afghanistan. Because of the terrain, most of the med evac missions are carried out by chopper. They typically have 20 minutes to fly to the patients, 20 minutes to stabilize and treat, and 20 minutes to get the patients to more medical care. It is one golden hour. Right now, even as I write this, these medics are sleeping in forward operating bases just behind the front line troops - with their boots on, and eyes half open in dusty desert tents waiting to get the call. Waiting for a chance to save their fellow soldiers who got the call before them.

Truth of the matter, nearly three-fourths of the time, the call they get is to take care of an Afghan local or soldier. In fact, if you look at the breakdown of operations performed at the coalition force run Kandahar Role III, the largest trauma hospital in the country, most are performed on Afghan patients. The local medical system in Afghanistan lacks the infrastructure to take care of most of these sorts of injuries. There is only one vascular surgeon in the country, two neurosurgeons and really no ability to perform cardiac surgery. It made me wonder what will happen to patients with trauma a year from now or in five or ten years.

If you look at pure numbers, for every 10,000 troops, 127 will be wounded in action. A tenth of those wounded will have traumatic brain injuries and several others will need amputations. Still others will have serious burns. It costs close to $20,000 per soldier to provide field care, and if you add in an air evacuation, the cost is closer to $50,000. At the Kandahar hospital, doctors are performing close to 300 operations a month, and that number is expected to increase over the next few months.

Of course, these numbers are meaningless to the tens of thousands of troops in Afghanistan right now and the tens of thousands about to head there. As you watch the speech tonight and the analysis over the next few days, try and remember the medical staff there as well. They are the ones embraced in that awkward medicine and military dance – they are the ones trying to repair the ravages of war.

Editor's Note: Medical news is a popular but sensitive subject rooted in science. We receive many comments on this blog each day; not all are posted. Our hope is that much will be learned from the sharing of useful information and personal experiences based on the medical and health topics of the blog. We encourage you to focus your comments on those medical and health topics and we appreciate your input. Thank you for your participation.

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Connie in California:

"My family will be flying for the holidays. Should we be concerned about being in an enclosed space for five hours?"

Answer:

Connie, more than 2 million people are expected to be flying over this holiday weekend and many have the same concern as you. The Centers for Disease Control and Prevention points out there are not many studies about the spread of flu on airplanes, but anytime people are in close quarters the chance for germs spreading is much higher.

If you are sitting next to someone who is coughing excessively or seems ill, that’s when you are most at risk. According to researchers at Purdue University, you’re most likely to get sick from the people sitting in your row or the row behind you. They actually developed an animation showing how germs move around an airplane. If you’re in this situation, there are things you can do to lessen your risk of getting sick. Point the air vent away from yourself and towards the sick person – that may help push the germs back at that person. Also, turn your body away from the person who seems ill and as we’ve been saying – don’t touch your face. Dr. Julie Gerberding, the former director of the Centers for Disease Control and Prevention, adds that you could ask a flight attendant whether a mask could be given to that person or if that person or you could be moved to another part of the plane. Gerberding also points out that the air on planes is circulated through a HEPA filter, so if you are several rows away from a sick person you’re unlikely to catch his or her germs.

Keep in mind, you can go a long way in protecting yourself by taking some simple steps. I know we talk about this all the time, but wash your hands frequently with soap and water. If soap and water aren't available, you can carry those alcohol-based hand sanitizers. Cover your nose and mouth with a tissue while sneezing and encourage people around you to do the same thing and avoid touching your eyes, nose and mouth. We touch our hands to our faces a lot. In addition, some people might consider carrying a disposable mask, especially if you're feeling sick yourself. Finally, the CDC recommends that you get vaccinated, if you can. That’s sometimes harder than it sounds. For more information, check out flu.gov and CNN’s special report on H1N1.  Have a safe trip, Connie

As a feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

From Elaine in New Jersey:

I attended a clinic this weekend for the H1N1 shots, and they administered the nasal spray to my 14-month-old! According to the CDC website it should NOT be administered to children under 2 years of age! I contacted the pharmacy where the clinic was held, and they took my contact info and said we will get back to me. Can you tell me is my child at risk?? I also have a call into my pediatrician. I also contact the CDC and was told they are not medical professionals.

Answer:

Elaine, it is easy to sense dismay and concern from your e-mail, and as a father I can certainly relate.

The reality is – yes – the nasal spray version of the H1N1 vaccine, which contains a weakened live flu virus, should be given only to people ages 2 to 49. We also know that children with conditions such as asthma may not be eligible for the live flu vaccine.

In order to ease your mind a bit, unless he or she has asthma, chances are very good that your 14-month-old will be fine.

The primary reason children younger than 2 do not get the nasal spray H1N1 vaccine is that it has not been tested in, and therefore is not licensed for, that age group. It is that simple. You need solid data to submit to the Food and Drug Administration before a medication can be approved for use in a particular population – that data do not exist for children younger than 24 months.

To ease your mind a bit more, rare complaints among adults and children taking the nasal spray form of the H1N1 vaccine are runny nose, sore throat, and sometimes fever. These symptoms usually go away within a couple of days. If they do crop up for your 14-month-old, you should not be too concerned, but if the symptoms get worse or your instinct tells you to, do see your pediatrician.

On the bright side of your predicament, your son or daughter is now vaccinated against H1N1. There are many parents who are still waiting to have their children vaccinated, so count yourself among the fortunate. Your child should soon have a second H1N1 vaccine dose – this time with the injectable form of the vaccine. And if you have not yet been vaccinated, you should do so – as the caregiver for your baby, you are eligible for these early doses of vaccine.

As a new feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here's a question for Dr. Gupta.

Question from Jane in Amsterdam:

"I fear having a stroke because I have high blood pressure and my life is very stressful. What are the signs to look for and what can I do to help myself?"

Answer:

Thanks, Jane, for the question. It’s an important topic and impacts people of all ages. As a neurosurgeon, I can tell you strokes don’t just strike older generations. Doctors today around the world are seeing people in the 30s, 40s and 50s having strokes. The reason? Mostly due to unhealthy lifestyles.

Jane you mentioned your life is very stressful and you have high blood pressure. These are two major risk factors of stroke. Other lifestyle factors that play a role include unhealthy diet, smoking,  lack of exercise and obesity. So any changes you can make in your life to increase physical activity, get your blood pressure in control will dramatically lower your risk. Studies show people with healthy blood pressure - less than 120/80 - have about half the lifetime risk of stroke as those with high blood pressure, or hypertension.

Knowing the early signs of a stroke is critical because immediate medical attention is needed to prevent long-term disability. What’s surprising is the majority of people ignore the early warning signs. In fact, a Mayo Clinic study found 58 percent of stroke patients brushed off the symptoms as another ailment, and delayed seeing a doctor for about 3 1/2 hours on average.

Time is critical because a stroke directly impacts your brain. There are two types, ischemic stroke and hemorrhagic stroke. An ischemic stroke is when the blood flow to a person’s brain is interrupted; hemorrhagic stroke occurs when the blood vessels actually burst in the brain.

Some strokes strike suddenly but more often than not your body will give you signals. Stroke patients often describe having the “worst headache of my life.” It comes on suddenly and can cause pain between your eyes, even a stiff neck. Suddenly feeling fatigued, dizzy and weak can be a signal. For example, you may be folding laundry or walking to a meeting and feel a strong, sudden loss of coordination. It’s also very common to feel numb on just one side of your body.

I can’t stress enough to tell your friends, neighbors, co-workers about these symptoms and don’t brush them off. If you are at high risk for a stroke and feel one of these symptoms suddenly occur, seek medical treatment as soon as possible.

And Jane, remember that strokes are preventable. I challenge you to get moving! Make a goal to exercise at least 30 minutes a day. It’s not only going to naturally reduce your stress levels, but will also help bring your blood pressure down and reduce your overall risk.

As a new feature of CNNhealth.com, our team of expert doctors will answer readers' questions. Here are two questions for Dr. Gupta.

From Kat in College Park, Maryland:

“Is it possible to get swine flu (or regular flu, for that matter) twice in the same season?”

Answer:
Once you’ve had the flu, your chance of getting it again in the same season is low. Your body builds antibodies to protect against it. This basically means if you contract that same exact strain, your body fights it off naturally, typically before you’d notice any symptoms. There are a couple of concerns, though, and one that we've been talking about almost since the beginning, and that is that the virus can mutate. It can start to change. If it mutated, a couple of things could happen. A person who has already had H1N1, would no longer be protected. But also, the people who get the vaccine being shipped out now, which is designed specifically to protect against this strain of H1N1, also wouldn’t have protection if it mutates. 

From Vanessa in Gholson, Texas:

“My kids are sick with flu-like symptoms. I’m not sure if I should take them to the doctor but would like to confirm if my children have H1N1 or not. Should we go?”

Answer:
Great question and one I’ve been getting a lot from viewers. Should a person with flu-like symptoms go to the doctor? For the vast majority of people reading this right now, the answer is no. You will have a few miserable days but most likely not need any medical attention whatsoever.

There are some high-risk groups that would need medical attention, but, a good rule of thumb is if you think you are sick enough that you would have gone to the doctor a few years ago for flu-like symptoms, then you can go this year as well. But don't treat this differently simply because it has a different name of H1N1.

As far as getting tested, this is really interesting. When we first started reporting on this virus back in the spring, health officials were trying to figure out exactly what the virus was and confirm whether it was H1N1. They were doing a lot of testing then to help investigate what areas of the country it spread to. But now we know this virus is pretty much everywhere. And the CDC isn’t recommending health providers test for it in most cases because they don't need that information anymore.   Also, the patient probably wouldn’t be medically treated any differently from the treatment for seasonal flu.

As a regular feature of CNNhealth.com, our team of expert doctors answers readers’ questions. Here’s a question for Dr. Gupta.

From Birgitta in Newcastle, Washington:

I think I already had the swine flu but do not know for sure if it was swine flu, do I take the vaccination anyway? Is it safe to take if I suspect that the flu I had was swine flu?

Answer:

Tens of thousands of people right now, like Birgitta, are suffering from or getting over the H1N1 virus. Those numbers will continue to swell as the flu season wears on, and these questions will inevitably come up over and over again.

Incidentally, I can relate. I contracted the H1N1 virus recently while reporting on the war in Afghanistan, and I was miserable for days. I got my immunity to H1N1 the hard way, so I can take a pass on the vaccine this year. But what about people who are not as sure, like Birgitta?

The bottom line is, unless you got a laboratory test confirming it, you cannot be sure that you actually got the H1N1 virus. There are several strains of influenza floating around out there this season, two of which are H1N1 and seasonal influenza. There are a handful of other strains you could have contracted.

The old adage, "Better to be safe than sorry," may apply here. Unless you're sure you had H1N1, the Centers for Disease Control and Prevention recommends that you get vaccinated. Even if you did, in theory, get H1N1 the CDC reports no evidence that subsequently getting the H1N1 vaccine would cause problems for you.

You can think about your vaccination like an insurance policy. If you did have H1N1 during your recent illness, then you're protected. If you did not, you're also protected.

If you're wondering when the vaccine will be available, the largest shipment of H1N1 vaccine is scheduled for mid-October. By then, the first 45 million doses of the vaccine will be ready, with another 20 million doses shipped out each week until December.

And don't forget, the CDC recommends that you get the seasonal flu vaccine as well.

By Dr. Sanjay Gupta
CNN Chief Medical Correspondent

It started as a cough. It wasn’t the kind of cough where something is temporarily stuck in your throat. It wasn’t the kind of cough where simply clearing your throat would’ve been adequate. This was the kind of cough that hurts when you do it. A stinging pain that makes you wince and guard and hope that you don’t have to cough again any time soon. I thought I might have a fever, but of course, I was in the middle of covering a war in Afghanistan, and the conditions were… well, hot. So, maybe it was that. Problem was, the next day I wasn’t feeling any better – in fact, I was worse. I woke up in my dusty desert tent and tried to step out of my sleeping bag. Two steps later, I almost hit the deck. Incoming. Except this wasn’t due to any sirens going off, this was due to my own body simply being unable to hold myself up. I was lightheaded and freezing cold – even though it was over 100 degrees outside at that early hour of the morning.

Dr. Sanjay Gupta, who contracted H1N1 in Afghanistan, receives treatment.

I was nauseated and my entire body hurt. I tried to explain away my symptoms with lots of different excuses. You don’t sleep much while covering a war. My bulletproof jacket didn’t fit perfectly and was very heavy. There was a lot of dust and dirt, and maybe I had what the Marines referred to as the Kandahar Krud. It turned out to be none of those things.

I remember looking over at my camera man, Scottie McWhinnie. He looked absolutely awful. He was wearing a scarf on his head, and it was completely drenched in sweat. He was coughing so loudly and frequently that I was really starting to worry about him – and about myself. We each had it, whatever “it” was. I made a command decision. As a physician reporter in a war zone, I was going to get us medical care. That prompted our visit to a battlefield hospital, not as reporters this time, but as patients.

It is worth pointing out the irony of a medical reporter getting influenza type A, which was then ultimately confirmed as H1N1. (The term swine flu is a misnomer, as this strain is made up of several different components, including swine, but also avian parts.) It really didn’t matter if I got tested, as my doctor told me. It was the only flu strain circulating and I had it, and so did Scottie. We both had high fevers, the lack of appetite, terrible sinus congestion, body aches, and yes – that hacking, come out of the blue.

I am not someone who gets sick, really ever. And this was the sickest I have ever been. I would’ve much preferred my own bed with all the comforts of home – including a wife who would’ve taken great pity on me and allowed me lots of rest and relaxation. Still, I am here to blog about it, after taking the requisite few days to stay at home and not spread my gift from Afghanistan to all my colleagues at work. In case you are curious, there wasn’t much the doctors could really do for me. Some Tylenol and a sinus decongestant (the same my wife would’ve given me). We also got IV fluids, given our inability to keep anything down. Within a couple days, I felt a lot better, and a few days after that – I was back to normal. It was a lot like… the flu – with a different name. A lot of people will get the exact symptoms I described above, and for most people, it will simply mean a few miserable days, hopefully spent in your home – and not in a war zone.