Radiation fear
Q In August 1998 I fell ill with a range of vague symptoms including recurrent headaches and nausea. My GP referred me to a consultant and I ended up having X-rays of my sinuses (four plates) and a head CT scan. I had already had X-rays of my skull (three plates) taken in November 1997 after a head injury. These X-rays proved to be normal and my doctor has now decided that I have probably been suffering from a virus. Although I am now starting to feel a lot better, I am very concerned at the damage that may have been done by exposing my brain to so much radiation. Do I have anything to worry about, and is there anything I can do to mitigate this damage?
A You have definitely not been exposed to dangerous level of radiation so you can afford to relax about that. Although X-ray exposure is cumulative, the fact that your skull X-rays were done a year before the sinus X-rays means the effect will have largely worn off so it's not as bad as having had them all at the same time. It is true that a CT scan is equivalent to more than 100 X-rays and that is why they really shouldn't ever be undertaken without a clear clinical reason. But it sounds as though in your case, the doctors were trying to rule out a brain tumour, which is obviously a justifiable use of CT scanning. The only thing you can do now is to minimise any future exposure to radiation by questioning whether X-rays are really necessary.
Contraception concern
Q I am 30 and have tried various forms of contraception including several types of combined pill (Mercilon, Marvelon) and the mini-pill. But I've nearly always experienced breakthrough bleeding which is probably the most effective contraceptive around because it stops me having sex altogether. Three weeks ago I started taking Microgynon and the same thing is happening all over again. Is this likely to stop eventually? I've heard you can have depot injections these days; would they be an option?
A This is such a common problem. Bleeding intermittently while on the pill is almost always a hormonal imbalance which can be corrected if only you can find the right pill for you. But it's very important not to attribute all ills to your hormones - so I'm sure you'll want to check that you've had a recent, normal cervical smear and that you have been tested for infections. If you're all clear on that front, you need a pill that is relatively high in the hormone progestogen that is similar to the naturally occurring hormone, progesterone, which keeps the lining of the womb in place.
Loestrin 30 is a high progestogen pill worth trying. Alternatively, one of the triphasic pills such as Trinordiol may be good. I wouldn't really recommend a depot injection such as Depoprovera; once injected you can't do anything about it for three months until it wears off and some women get a lot of breakthrough bleeding with this method. Admittedly, you may one of the lucky 40% who have no periods at all on them, but I'm not sure it's worth the gamble.
Spinning out of control
Q Ever since my early childhood (I am currently 19 years old) I have experienced regular attacks of nausea and giddiness. The symptoms are difficult to describe as the sensation occurs in my head, not my stomach. I feel as if the world is spinning, although visually things remain stationary. The "spinning" sensation causes feelings of nausea, and although often very severe, I am never actually in danger of vomiting. Movement and even looking around during these attacks causes the sensation to worsen, and I am left sitting or laying in one fixed position for hours.
I usually experience these symptoms once every couple of months or so and attacks can range from two hours to 12 hours. I occasionally experience them at night in bed. I don't know if it is related but I also suffer from extremely severe travel sickness. It has also been suggested to me that it could be related to minor allergies that I have to pollen, dust and animal fur, although I am not convinced of this myself.
A The most likely cause of your problem is called benign positional vertigo. It causes brief but severe attacks of vertigo (dizziness) which come on when you turn your head. It can be caused by a head injury but more commonly comes on after viral illness or as the result of long term middle ear infections. Most sufferers learn to avoid turning their head during attacks, but obviously that's not always possible. There are formal exercises you can be taught which help relieve the symptoms. Most people get better even without treatment after six months or so.
If you also experience hearing loss and ringing in the ears, you may have Meniere's disease - a problem in the inner ear which can cause permanent hearing loss. I would ask your GP for a referral to an ENT surgeon for a proper diagnosis and help with the exercises if benign positional vertigo is the problem.
• These answers are intended to be as accurate and full as possible, but should never be used as a substitute for visiting a doctor and seeking medical help.
If you have a question for Dr Robinson, email drann@dircon.co.uk or write to her c/o The Health Editor, The Guardian, 119 Farringdon Road, London EC1R 3ER. She regrets that she cannot enter into personal correspondence.
