Q How is a blood group passed on? I was surprised to find I am A negative which I believe is quite rare. Would one of my parents have to be A negative to pass it to me? A nurse bet I was of a rare blood group because I had allergies to many things. Is there any truth to this?

A I hate to disillusion you, but it isn't rare. More than 40 per cent of people in England have an A blood group - it's thought to come with Anglo-Saxon inheritance. (Celts - the Welsh, Cornish and Scots - are slightly more likely to have an O group). Fifteen per cent of all Brits are rhesus negative, regardless of our O, B, A or AB group status. There's no relationship between blood group and susceptibility to allergies. Vague relationships have been mooted between particular blood groups and illnesses, like stomach ulcers and cancer, but they are not strong enough to predict for each individual the diseases they are likely to develop. As for your parents, one or both would have had to possess the A' group gene. Both would have had to carry the rhesus negative gene, but they might have been rhesus positive, with both carrying the negative gene as a recessive. By inheriting a negative one from each parent you would turn out to be negative. It's complex, and you would have to know your parents' blood groups to be sure.

Q For years, my upper arms have been covered in tiny 'bumps' (almost like goosepimples) and some have white heads on them. I've seen them on other people as well. I've tried everything to get rid of them but to no avail. What are they and how do I get rid of them?

A Without seeing them it is difficult to make a diagnosis, but it sounds as if you are describing your hair follicles - you have them on your arms just as you do on your head, except that the hairs don't grow out of them in the same way as they do from your scalp. The description that they are like goosepimples clinches it for me, because that's exactly what goosepimples are - raised hair follicles. The white heads are probably tiny beads of sebum, the secretion that is produced by hair follicles. If that's the case you can't get rid of them: they are a normal part of you. However, do ask your doctor to see them, because they may be chronically infected (a form of seborrhoea) and there are skin preparations on prescription that may help you.

Q What is TATT?

A It stands for Tired All The Time, and is self-descriptive. Trouble is that it can have many causes, from anaemia (often in women with heavy periods who lose a lot each month), to depression, low thyroid function, chronic infections, kidney disease, heart disease, and even early cancer. So when a patient complains of being TATT, we need to find out why, if we can. That means a full examination and often blood and other tests. It's not in the dictionaries because it's one of those annoying shorthand terms medics and nurses use.