Calf feeling always tired, common causes are as follows: first, the calf muscle chronic strain injury, due to the existence of chronic strain injury, local will produce aseptic inflammation, irritation will produce fatigue, tired feeling. Second, it can be seen in the lower limb nerves are affected, such as lumbar disc herniation, pear-shaped muscle outlet syndrome, compression of the lower limb sciatic nerve, resulting in calf fatigue, fatigue, or the sciatic nerve also due to neuritis will also appear to feel abnormal, feel very tired. Third, visible in the calf blood circulation abnormalities, such as cold, varicose veins, phlebitis, etc., will lead to poor blood circulation, calf muscle groups of metabolic products can not be removed in time to excrete, irritation produces a very tired feeling. Certain ionic changes can lead to abnormal muscle function, such as low potassium, low calcium, potassium and calcium are important ions to maintain muscle strength, low potassium, low calcium will lead to localized tired feeling.