By contrast, the only previous tummy upset I have had was very mild. That time I felt off-colour for an hour, threw up once, took 10mg hydrocortisone then slept for an hour and felt fine again.

This time I woke at 3am with a headache, just before my pre-school daughter woke up wailing because she was throwing up in her bed. By 4am when we had her settled again, I was getting nauseous myself. I was cautious enough to place a packet of hydrocortisone, a glass of water and a bucket by the bed. I swallowed 10mg hydrocortisone with a sip of water and dozed.

By 5am I was feeling worse, with a thumping headache and nausea, so I took another 10mg. By 6am I was no better, so I took another 10mg. At 7am I sat up to take another 10mg and vomited it up again. I immediately took another 20mg, hoping I could keep it down if I lay still. I did keep it down, but I still felt terrible: shivering and sweating, a pounding headache, deep, black nausea.

Fortunately my husband was able to stay home from work, take care of the children, and clean up after me and our daughter, as we were both throwing up. Even moving my head on the pillow triggered intense waves of nausea and I couldn't easily have got out of bed while it lasted.

Around 8am I sat up to take another 10mg, and the effort of sitting up again made me vomit up the tablet. Again I swallowed another 20mg straight away, lay as still as I could, and kept it down. By now I was feeling pretty confused. Then I threw up again around 9am, swallowed another 20mg, and lay there dozing. At 10am, when I swallowed another 10mg, the nausea was starting to ease.

Some time mid-morning, my three-year old son slipped into bed beside me.  He was recovering from the same tummy bug and slept most of the day.  While we both lay there, I had an interesting example of the extreme muscle weakness you get with Addison’s.  I awoke with a start, thinking I was having a heart attack, with the sensation of an incredibly heavy, hot weight across my chest.  Then I realised that crushing weight was nothing more than my young son’s arm lightly stretched out across my ribs.

I dozed until after 11am, when I swallowed another 10mg. Then I dozed until nearly 1pm, when I swallowed another 10mg. Around 3pm I took the last 10mg in the blister-pack and got up to go to the loo. I still had the headache, but the nausea was gone.

I had swallowed 150mg hydrocortisone in under 11 hours - 20mg of which I had vomited up again straight away - and I had only just avoided the need for an emergency injection.

Once I was through the worst, I was surprised by how quickly I bounced back again.  By evening I was well enough to prepare and eat a light meal, although still rather weak and tired.  By contrast, my poor daughter couldn’t keep anything down for the next two days.

The night I was sick is the week-night my husband is usually out of town for his work. By the time I had begun to vomit, I was weak enough that I would have had trouble crawling to the phone to ring for help and could not easily have got my injection kit down from the cupboard, let alone used it.  If I had been on my own with the kids I would have been unable to care for them or myself. So please learn from my experience and be quick to take extra hydrocortisone when you need it.  If you live alone, make sure you keep a phone by your bed so that if you are sick, so you can ring for help if you need to.

Bad Bugs -The doctor's view

Getting the amount right when extra hydrocortisone is needed is always a matter of judgement.  At the end of the day it is better to play safe and temporarily overdose the hydrocortisone than to give not enough.  In this case, I think taking an extra 20mg at a time was probably enough.

If somebody vomits they should immediately take twice the dose they normally take with a small glass of water.  If they vomit more than once then it is time to use their emergency  injection. Giving an injection is not a failure in any way, just a safe way of delivering the hydrocortisone. If vomiting continues and no hydrocortisone can be absorbed orally then it is time for an admission to hospital and further supervised injections for a brief period.

In this case, I think it is not a question of being more aggressive with the oral hydrocortisone dose but probably resorting to an injection earlier, as I say after vomiting more than once.

The general rules are as follows:

• Double the dose of hydrocortisone if very unwell or with a temperature, and stay at double dose for at least 48 hours or until the temperature has gone down.

• If vomiting take double the normal dose of hydrocortisone immediately afterwards. If vomiting more than once it is time for an injection.

• If vomiting continues after the injection, then the GP needs to be summoned and the possibility of a brief hospital admission considered.

• When you ring the GP, always remind them that you have Addison’s disease and need priority attention for emergency treatment.  Remember that GPs generally want to know sooner, rather than later, when their patients are severely ill.

John Wass

Professor of Endocrinology,

The Radcliffe Infirmary,

Oxford

UK