Q: I'm a 54-year-old woman who is 5-foot-1 and weigh 110 pounds. I'm not medicated. I get a yearly physical. I exercise regularly and have done so for most of my adult life. When I ride my bike, I'm usually out for at least three hours. My heart rate averages 155 and peaks at 175. I'm always still able to breathe and talk, and when I rest my heart rate comes down quickly. But this rate is a lot higher than the target heart-rate zone for my age -- 116-149, according to an Internet search. What are your thoughts?

A: Target heart rate is a good example of a characteristic that varies a great deal from one person to another. The ranges that are published are right for many people but not for everybody. The formula for women is even less accurate than the one for men. It is particularly bad for athletes, who tend to have heart rates similar to those of younger women. The fact that your heart rate comes down quickly is another sign of good fitness.

The best way to find your maximum heart rate is to have a supervised maximal exercise session. However, being able to talk during exercise remains a good way to be sure you are properly regulating your exercise.

Q: I understand that THC is the active drug in marijuana. Where medical marijuana is legal, why isn't THC extracted and prescribed?

A: Synthetic THC has been available for years as the prescription medication dronabinol (Marinol).


It is Food and Drug Administration-indicated to treat nausea associated with chemotherapy and to help people with advanced HIV gain weight, but it is used "off label" for pain, headache and other symptoms.

It does have the benefits you mention, but many people think the synthetic drug does not work as well as marijuana, which has several types of THC, not just the delta 9 that is in Marinol. It is a class III restricted substance.

Medical opinion is divided about whether natural marijuana has any benefit over the synthetic, exactly dosed and purified pharmaceutical product. In addition to the many other active substances in natural marijuana, oral use is different from smoked, since any drug taken orally must go through the liver, which metabolizes it into yet more compounds.

The American Medical Association has recommended further study before it is recommended for general use.

Q: My son is being treated for bipolar, anxiety and depression. His weight has increased so much that this is causing him even more depression. His physician has told him there isn't anything he can do. My son walks for exercise and doesn't overeat. Is there a solution?

A: While psychiatric disorders can cause weight gain -- weight gain and weight loss both are signs of depression -- the more likely issue is that one or more of your son's medications is making him gain weight. Many of the medications have weight gain as a side effect; in some cases, the weight gain can be dramatic.

Physicians are slowly realizing that weight gain in this situation isn't the patient's fault, and that if there is a fault, it is ours as physicians, for failing to recognize the effects medicines have in causing weight gain.

There is no simple solution. The psychiatrist must work with his internist or with a weight-loss specialist to find medications that are less likely to cause weight gain and are more likely to promote weight loss.

In some cases, your son may be prescribed additional medicines to directly combat the weight gain.

Q: My great-niece is 9 years old. She saw her doctor for a bad complexion, and was told that she is stage 3 for puberty. What does this mean, and how many stages are there?

A: Puberty is a process, not an event. It goes on normally for several years. There are five stages of puberty, usually called Tanner stages. There are specific criteria for development that correspond to each stage.

Nine years old is on the younger side for Tanner stage 3, but puberty starts at different times for different people, with significant differences that run in families and by ethnic background. 

Your great-niece's complexion issue probably relates to high levels of adrenal hormones, which start increasing even before puberty. Very high levels early in puberty should raise concern for a condition called congenital adrenal hyperplasia, although most cases of acne in early puberty are quite normal. If the gynecologist is worried, some simple blood and urine tests can tell you more.

Q: I'm 62 years old, and I'm starting to lose my high-pitch hearing. I now try to protect myself from further damage by keeping the TV volume low and wearing earplugs when I mow, weed, vacuum, ride my motorcycle, etc. My problem is that some of these new automatic-flush toilets sound like jet engines. My ears have gotten worse, and I think it's from the noise of these toilets. Do you have any idea what the decibels are on these new type of toilets that make you feel like they are trying to suck you down the hole?

A: You're right; the high-pressure automatic toilets are quite loud. Peak loudness for one brand I found was 86 decibels (dB), compared with 71 dB for a standard toilet. A 15 dB difference might not sound like much, but it's more than 30 times louder. Sustained noise over 85 dB can lead to hearing loss. I understand that the newer models are much quieter.

Email questions ToYourGood Health@med.cornell.edu.