Pain in one of the tendons of the arm is mainly due to strain or injury of one of the muscles of the arm. For example, the arm area of the triceps brachii, biceps brachii, brachioradialis and other single muscles, these muscles due to lifting, lifting heavy objects, or strenuous exercise is prone to force more than the normal load of the muscle and thus strained; or frequently for a certain action, the muscle tissue continues to be tense, fatigue will be formed strain. These will produce aseptic inflammatory lesions in the local area, the metabolites will produce stimulation of the surrounding peripheral nerves and thus feel the pain, and if you continue to activities, strains and strains will be further pulled, stimulation of the location, resulting in more pronounced pain. Muscle tissues become more tense and blood circulation slows down when exposed to cold, and the slowing of venous return leads to a buildup of inflammatory metabolites and the gradual formation of inflammatory edema, which can also aggravate the pain in a particular tendon.