A doctor said it was all in my mind, and gave me some tranquillisers. They have not helped, and only make me sleepy. Sometimes I fall asleep while my fiancée is waiting for me to make love to her.

I have noticed that I never get 'morning erections'. My friends have told me that men should get an erection every single morning when they wake up. Is this true? And is my lack of morning erections an indication of anything serious?

A. I am sorry to hear about this. When a man who is in his 20s complains of erectile dysfunction (ED), the cause is usually psychological.

You see, if a young male is anxious or fretting, the glands inside his body release stress chemicals, such as noradrenaline. These stress chemicals are the enemy of erection - because they make it extremely difficult for blood to flow into the penis. Therefore, it cannot get stiff.

So, it is likely that some form of performance anxiety is affecting your erections. However, I don't think that tranquillisers are the best treatment for that. As you have discovered, they tend to send you to sleep!

Usually, when a young guy is fretting about sex, the best thing is for him to get counselling to build up his confidence.

In your case, there might be an additional factor. I say this because of the fact that you are not getting morning erections.

Those 'wake-up erections' are not really under the control of the mind. So when a guy is anxious about having sex, that anxiety will not usually affect his morning stiffness.

Therefore, when a man stops waking up with an erection, it is sometimes a sign that something physical (rather than mental) is wrong. Incidentally, what your friends have told you about these morning erections is not quite true. The average young man doesn't get one every single morning of the week. However, researchers in the United States have found that at your age, the average guy gets nearly two per week.

In summary, it is possible that there is some physical cause for your problem. For that reason, I think you should get a full medical check-up, including an examination of the testicles.

Most important, you should have a blood test done to find out if your level of testosterone (male hormone) is normal.

If it's low, which I suspect may be the case, the doc could give you some testosterone in the form of tablets or injections or a skin gel. There is a good chance that this could help your erections. I wish you well with your marriage plans.

A. It is very likely that these long periods are making you lose far too much iron in the menstrual blood. I suspect that as a result, you have become anaemic - that is, weak-blooded.

Symptoms of severe anaemia include weakness, tiredness and breathlessness. And it has to be corrected - fast.

Please see a doc ASAP. She will examine you and do a blood test for anaemia and other things.

If you do turn out to be anaemic, she will put you on iron tablets to build up the strength of your blood. Also, I am sure she will do something to help you have much, much shorter menses.

A. I must tell you that the ideal poundage for a man your height would be between 145 and 180 pounds. In other words, you are at least 100 pounds overweight.

There is an important figure that doctors use in order to calculate whether somebody is obese. It is called the basal metabolic index, or BMI. It is obtained by a simple calculation involving the person's height in metres and weight in kilograms.

In order to be healthy, a person's BMI should be between 20 and 25. Yours is 38.7. A BMI of 38.7 means that you are likely to become ill as a result of your excess weight, so I urge you to start slimming down now.

I have never encountered a patient whose body started to vibrate during exercise. But your itching behind the knees and elsewhere might be due to a fungal infection, because such infections are common in cases where two bulging areas of skin are rubbing together. Get a full medical check-up from a doctor who can assess these complex symptoms. She can also give you a good diet sheet.

A. It is fact. Many men and women start out fertile, but are made sterile by STIs. Your wisest course now would be to ask a doc to do a sperm test to check your fertility rating.

Your email indicates that you do have a history of STIs, so it would be a good idea to get the doctor to do tests for those as well.

Email questions about medical problems to saturdaylife@gleanerjm.com.