People do go to high altitudes with pre-existing medical conditions. If you suffer from a condition, you must talk to your doctor about whether or not you should go to high altitude and, if you do, how you should take care of yourself.
With any condition there is more risk to health when travelling to remote locations. The key is to lower this risk as far as possible. Be prepared to give up part or all of your trip for safety reasons.
Always carry your medical information letter / MedicAlert bracelet.
Each day, write down medicines taken and any changes in your condition.
If symptoms worsen avoid further ascent, consider the possibility of altitude related illnesses and descend as necessary.
Be honest with everyone about changes in your medical condition.
Look after your family, friends and other travellers.
See your doctor / specialist at least 6 months before your trip. Find out about the risks your condition poses for travel at high altitude.
Make a medical plan and what, if any, support you will need. Find out what medical help may be available. Think about what you will do if things go wrong.
Make a contacts list for your condition for home / where you are going.
Make everyone aware of your medical condition, the signs, symptoms and treatment. Your illness could affect everyone in your group.
Get first aid / medical training for yourself and others if necessary.
Make a kit with your medicines. Make clear labels and instructions. Have spare supplies and split the kit between people to lower the chance of losing it all.
Ask your doctor to prepare an official letter, explaining your condition, treatment and contact details (translate if necessary).
Tell your travel nurse about your conditions before vaccinations, etc.
Get medical insurance that covers your condition and the risks of the trip. It can be hard, very expensive or impossible to cover what some people want.