Lupus. Lupus is a chronic autoimmune disease, meaning the body's immune system creates antibodies that attack and damage healthy tissues. Lupus can cause inflammation of the joints, including the hip, as well as the skin, heart, lungs, and kidney.

Gout. Gout is a form of arthritis that occurs when excess uric acid, a bodily waste product circulating in the bloodstream, is deposited as needle-shaped monosodium urate crystals in tissues of the body, including the joints. For many people, the first symptom of gout is excruciating pain and swelling in the big toe – often following a trauma, such as an illness or injury. Subsequent attacks may occur off and on in other joints, primarily those of the foot and knee. Gout less commonly causes hip pain.

More you should know about gout.

Psoriatic arthritis. Psoriatic arthritis is a form of arthritis accompanied by the skin disease psoriasis. The skin disease often precedes the arthritis; in a small percentage the joint disease develops before the skin disease. The arthritis can affect both large and small joints, including the hip.

Learn more about psoriatic arthritis.

Infectious arthritis.  Also called septic arthritis, infectious arthritis refers to arthritis that is caused by an infection within the joint. Infectious arthritis is often cause by bacteria that spread through the bloodstream to the joint. Sometimes it is caused by viruses or fungi.

Learn more about septic arthritis from the National Library of Medicine.

Learn about risk factors for hip arthritis.

Polymyalgia rheumatica. An inflammatory disorder that causes widespread muscle pain and stiffness, polymyalgia rheumatica mainly affects the neck, shoulders, upper arms, thighs and hips. The disease often comes on suddenly and resolves on its own in a year or two.

Learn more about polymyalgia rheumatica.

Osteonecrosis. Also called avascular necrosis or aseptic necrosis, this condition occurs when diminished blood to an area of bone causes it to die and eventually collapse. Blood flow may be blocked due to a number of causes including a clot, blood vessel inflammation or use of corticosteroid drugs. The hip is one of the most commonly affected joints.

Learn more about osteonecrosis from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Paget's disease of the bone. Paget’s disease is a chronic disorder in which excessive breakdown and formation of bone causes the bones to become enlarged, misshapen and weakened. The disease usually does not affect the entire skeleton, but just one or a few bones. If the pelvis is affected the disease can cause hip pain.

Learn more about Paget's disease of the bone from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Sciatica. This is inflammation of the sciatic nerve. The largest nerve in the human body, the sciatic nerve runs from the lower part of the spinal cord, through the buttock and down the back of the leg to the foot. The most common causes of sciatica include compression of the nerve where it exits the spine by a herniated disc, or a rupture of one of the structures that cushions the vertebrae in the spine. Sciatica may be felt as a sharp or burning pain that radiates from the hip.

Learn more about sciatica from the American Academy of Orthopaedic Surgeons.