Otherwise, you may have no symptoms for 1 to 3 months. But the symptoms worsen quickly over a few days to those of a severe illness of the central nervous system. The muscle spasms can include the muscles of the throat and voice box, so that it is very painful and difficult to swallow. Perhaps this is why a rabies-infected person avoids the sight, sound, and drinking of water, a condition called hydrophobia. Once these symptoms of severe illness have begun, coma and death follow in 3 to 20 days.
Rabies is very difficult to diagnose.
Because of the length of time between exposure and illness, it may not even be suspected as a cause of illness. The usual laboratory tests are not helpful. There is no test to detect the virus before it has invaded the brain. The only reliable way to test for the virus in the brain is to cut out and examine a piece of the brain, which is a drastic measure and normally not helpful because of the lack of curative treatments available for rabies at this stage. Rabies may be diagnosed before you have symptoms if the animal that bit you is quarantined for observation or killed.