The immune system is responsible for protecting us from disease, but sometimes it fails to work properly, and this can lead to disability. Acquired immune deficiency syndrome is caused when an HIV infection damages immune cells and suppresses the immune system. On the other end of the spectrum, abnormal immune activity that causes inflammation or the build-up of antibodies is responsible for autoimmune diseases like Grave's disease, multiple sclerosis, myasthenia gravis, Hashimoto's disease, and even psoriasis, as well as connective tissue disorders such as rheumatoid arthritis, lupus, and scleroderma. Social Security treats disorders of the immune system seriously, and has disability listings that lay out the criteria for qualifying for disability for most of these diseases. For the other immune system-related medical conditions, Social Security looks at how the symptoms of the disease are limiting your abilities and activities.