Does sarciatica go alone by rest?what should not a person do or avoid?

See other answer: It will help greatly to rest, but you can do other thins also, including medications and physical therapy.

Yes it can: Time, rest, activity restriction, medication, physical therapy, epidural steroid injections, chiropractic, guided exercise - some or most in combination as treatment options with 90% resolving without surgery. 75% are better within 3 months of onset of their leg pain. Lifestyle changes may be needed in terms of weight control, exercise and not smoking.

It can: Sciatica is usually caused by lumbar disc herniation. This goes away in most people with some time. One should avoid hyperflexion, hyperextension, significant twisting motion, heavy lifting. Pt and pain management injections can be very useful, if these things don't work surgery maybe an option. However if you have leg weakness or changes in bowel/bladder function seek emergent attention.

Possibly: If you were in weird positions or flexing/twisting your body alot during activity or exercise you can cause disc herniation so it is possible. If it does not improve, see your doctor for further evaluation.