Potassium deficiency can cause that, too. I had a similar problem about 20 years ago, & finally found a doctor that was willing to consider the possibility that I wasn't just neurotic. My hands would draw up so bad that my fingernails would dig holes in the palms of my hands. Turned out that I was so low on potassium that I was in danger of heart failure. It was caused by an adrenal tumor. Had the adrenal gland removed, & it fixed the problem.
If you take medicine for your blood pressure, it can also cause low potassium.
It could also be magnesium deficiency. You really should have a blood test to check your potassium & magnesium. It can kill you if it gets low enough.
He that saith, I know Him, and keepeth not His commandments, is a liar, and the truth is not in him. 1John 2:4
Job5:20: In famine he shall redeem thee from death: and in war from the power of the sword.
22: At destruction and famine thou shalt laugh: neither shalt thou be afraid of the beasts of the earth.