The treatment of small amount of fluid in the left shoulder joint mainly includes general treatment, drug treatment, physical therapy and so on. 1. General treatment: A small amount of fluid exists in normal human shoulder joint, which can play a lubricating role. If there is only a small amount of fluid in the left shoulder joint, patients are advised to reduce the activities of the left shoulder joint, pay attention to rest, and brake if necessary, which can be absorbed by themselves. 2. Drug therapy: patients can take oral non-steroidal anti-inflammatory drugs, such as celecoxib, etoricoxib, ibuprofen, etc., which can reduce the inflammatory response of the shoulder joint, and the pain, if any, can also be reduced. You can also use topical diclofenac diethylamide cream, which can also play the role of anti-inflammatory and pain relief. 3. Physical therapy: low-frequency pulse magnetic therapy, acupuncture, professional massage, etc., can better promote the absorption of local fluid. All of the above medications should be used under the guidance of a doctor. If you find a small amount of fluid in the left shoulder joint and the symptoms are not relieved after resting, it is recommended to consult a doctor in time, make a clear diagnosis and follow the doctor’s instructions for treatment.