I have numbness in my index, middle, & thumb. the pain gets so bad especially at night while i'm asleep, why & what is this?

Median nerve: irritation ( neritis) sometimetime an early sign of carpal tuneel symdrome and certainly requires evaluation and treatment.

Need evaluation: The pain and numbness are due to pressure on the nerve that supplies this area. This is generally due to arthritis in the cervical spine or cervical disc disease. It often responds to physical therapy, but sometimes requires surgery. You need an evaluation by a physiatrist, a neurosurgeon, or an orthopedist.

Hand numb at night: Numbness of the thumb side of the hand at night can be due to nerve compression from the position you are sleeping in. This is often due to neck arthritis or weakness, or problems . A neck roll, for strengthening the neck muscles with exercise might prevent this. If not, a doctor, chiropractor or therapist might help you. They can test you in certain positions on exam to see what causes symptoms.

CTS: You are describing classic symptoms of Carpal Tunnel Syndrome. Try a wrist/hand support brace at night when you sleep. It may help quite a bit. If it does not, irritation of the nerves that go into the fingers from a source up higher (in the neck) may be the cause and evaluation by healthcare provider needed. Hope this helps. Best of luck