Thumb muscle throbbing may be caused by physiological phenomenon, tenosynovitis, tetany and so on. 1. Physiological phenomenon: Repeated grasping movements of the hand or prolonged contraction to maintain a position may result in involuntary muscle contraction, spasm and lead to the phenomenon of throbbing. 2. Tenosynovitis: excessive use of the thumb, tendon sheath and tendon excessive friction, tendon sheath tissue aseptic inflammation. It can show localized pain, pressure pain and symptoms such as limited joint movement and muscle throbbing. 3. Tetany: A group of endocrine or nutritional disorders in which free calcium in the blood is lowered due to vitamin D deficiency or hypoparathyroidism. Reduced free calcium in the blood can lead to increased neuromuscular excitability, resulting in the phenomenon of thumb muscle throbbing. If thumb muscle throbbing persists without relief, you should go to the hospital in time and follow the doctor’s instructions for treatment to avoid delaying your condition.