I have diabetes and although my cholesterol isn't particularly high, my doctors say I should take a statin drug every day to lower it further. They say it is a particular priority for diabetics. Is that right, and why?

Unfortunately, people with diabetes have a higher risk than the rest of the population of developing heart attacks and strokes, so we need to do what we can to reduce it. A trial in more than 18,000 people with the common form of diabetes (type 2) showed that statins, by reducing cholesterol levels, cut the risk of heart attacks and strokes by one-fifth. Put another way, if 1,000 people with diabetes took a statin, there would be 42 fewer heart and brain events over the next five years. Use this evidence to base your choice on whether or not to take one.

My seven-year-old has small, red, itchy lumps in his skin which started on the backs of his hands and between his fingers, and are spreading up his arms. They itch worst at night. He scratches until they are sore. Calamine doesn't help. What can this be?

It sounds like scabies, which is caused by a tiny, burrowing mite. Your doctor will have to see him to confirm the diagnosis and treat it accordingly. Happily, treatment is very successful. But you will have to tell his school, because it spreads through a classroom like wildfire. And your whole family may have to be treated, as everyone in the house may be infected.