What would cause sweaty feet? sciatica? covid?

For how long have your feet sweat. If you have any of the ailments that you have mentioned, you would have additional symptoms. You might try some foot powder. Also, please consider seeing a Doctor of Podiatric Medicine.

Excessive sweating of the feet is called hyperhidrosis. It is more common in men than women. Sciatica is not the cause of it and I have never seen Covid be the cause either however covid can have odd symptoms in some people. There is roll-on and spray-on anti-perspirant for feet that can be purchased without a prescription.