I wake up each morning unable to make a fist in my left hand. it doesn't hurt, just feels uncomfortable. it loosens up later in the day, but begins to tighten again in the evening. it started about four months ago. what does this mean?

Thoracic Outlet -TOS: Thoracic Outlet Syndrome (TOS). The symptoms from the nerve compression cause pain, loss of sensation, and decreased function in the hand. See your doctor for definitive diagnosis and treatment.

Varries: There are multiple potential causes. If you are also experiencing numbness at times into the first three fingers, you may have carpal tunnel syndrome, in which symptoms are usually worse at night. Arthritis in the wrist or Tendonitis can cause similar symptoms, don't hesitate to be seen.

Arthritis mild: Early morning stiffness is often mild early osteoarthritis. Another problem can be trigger finger or tendinitis but licking or clicking may be present for this. Heat up warm showers warm water often helps am symptoms. Cool down. Or ice for pain after activity