Swelling of finger joints after waking up in the morning may be caused by improper sleeping position, rheumatoid arthritis and tenosynovitis. 1. Improper sleeping position: If you lie to the right side or to the left side for a long time during the night sleep, the blood vessels and lymphatic vessels of one side of the upper limb may be compressed, resulting in blood and lymphatic reflux being affected, which may cause the symptoms of swollen finger joints after waking up in the morning. 2. Rheumatoid arthritis: rheumatoid arthritis is an autoimmune disease that mainly involves the peripheral joints, with common symptoms of morning stiffness, joint swelling and joint pain, along with the progress of the disease may also appear joint deformity and joint movement difficulties, so the patient’s finger joints after waking up in the morning is not excluded from rheumatoid arthritis. 3. Tendovaginitis: tendovaginitis is caused by infection, strain injury, trauma and other reasons, leading to the outside of the tendon in the double casing-like synovial tube inflammation caused by the patient often appear in the affected joint pain, swelling and other symptoms. There may be other reasons for the swelling of the finger joints after waking up in the morning, and it is recommended that patients with long-term or recurrent swelling of the finger joints go to regular hospitals and receive standardized treatments as prescribed by the doctor.