The soreness of the arm when holding something heavy may be caused by physiological factors, chronic strain, acute injury, frozen shoulder and so on. 1. Physiological factors: heavy physical labor, resulting in the accumulation of local lactic acid metabolites, which can cause local symptoms of soreness, in carrying heavy things, may make the symptoms of soreness more obvious, should be reasonable rest, generally can be improved by itself. 2. Chronic strain injury: joints or muscles have chronic strain injury, there is aseptic inflammation, in carrying heavy things can lead to injury aggravation, will cause arm pain symptoms. 3. Acute injury: If the local muscle is strained, when you carry heavy things, it will cause pulling on the damaged muscle, which will cause soreness and pain, and it may be accompanied by redness, swelling and other symptoms. 4. Frozen shoulder: taking heavy things may make frozen shoulder aggravate, cause arm pain, manifested as upper arm pain, can lead to activity limitation when serious. If you have arm pain when carrying something heavy and have other abnormal symptoms, it is recommended to consult a doctor as soon as possible for examination and treatment.