A white membrane at the back of the throat when you have a sore throat is a normal occurrence. This happens when the problem is quite severe, and has been left unchecked for a couple of days. While this membrane is not a sign of infection, beware - you may possibly have an infection which would need medical attention. To answer your question, the membrane by itself is not dangerous. It is in fact, a way of protecting your tonsils from infection of any kind when you have a cold, and also of protecting them against getting rubbed raw.
There are also several easily effective ways of getting rid of it. One of the most effective remedies is to have warm diluted orange juice. Gargling with hot salt water will also help in providing relief. You can add a pinch of turmeric to this water as well. Turmeric is known for its healing properties. Have a hot tea made with lots of ginger and five or six cloves thrown in. Make sure you boil this for at least 15 minutes, and then have it as hot as you can. Avoid sugar. Opt instead for jaggery, which is soothing and is also known to have some healing properties. After trying these remedies for a whole day, if the membrane is still not gone, please get medical help. It could also be a warning of diphtheria, especially in children.
answered by M W