Idiopathic or unknown cause (idiopathic intracranial hypertension, a common cause in otherwise well people especially younger women)
CraniosynostosisOne of the most damaging aspects of brain trauma and other conditions, directly correlated with poor outcome, is an elevated intracranial pressure. ICP is very likely to cause severe harm if it rises too high. Very high intracranial pressures are usually fatal if prolonged, but children can tolerate higher pressures for longer periods. An increase in pressure, most commonly due to head injury leading to intracranial hematoma or cerebral edema, can crush brain tissue, shift brain structures, contribute to hydrocephalus, cause brain herniation, and restrict blood supply to the brain. It is a cause of reflex bradycardia. Low ICP
Spontaneous intracranial hypotension may occur as a result of an occult leak of CSF into another body cavity. More commonly, decreased ICP is the result of lumbar puncture or other medical procedures involving the brain or spinal cord. Various medical imaging technologies exist to assist in identifying the cause of decreased ICP. Often, the syndrome is self-limiting, especially if it is the result of a medical procedure.If persistent intracranial hypotension is the result of a lumbar puncture, a "blood patch" may be applied to seal the site of CSF leakage. Various medical treatments have been proposed; only the intravenous administration of caffeine and theophylline has shown to be particularly useful.
Lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs. The most common and most severe form is systemic lupus erythematosus. Signs and symptoms
Symptoms vary from person to person, and may come and go. Almost everyone with lupus has joint pain and swelling. Some develop arthritis. Frequently affected joints are the fingers, hands, wrists, and knees. Other common symptoms include:

chest pain during respiration
joint pain (stiffness and swelling)
painless oral ulcer
fatigue
weight loss
headaches
fever with no other cause
Skin lesions that appear worse after sun exposure
general discomfort, uneasiness, or ill feeling (malaise)
hair loss
sensitivity to sunlight
a "butterfly" facial rash, seen in about half of people with SLE
swollen lymph nodes

Photosensitivity
Photosensitivity is the amount to which an object reacts upon receiving photons especially in visible light. Photosensitivity is a known symptom of lupus, but its relationship to and influence on other aspects of the disease remain to be defined. Causes of photosensitivity may include:

change in autoantibody location
cytotoxicity
induction of apoptosis with autoantigens in apoptotic blebs
upregulation of adhesion molecules and cytokines
induction of nitric oxide synthase expression
ultraviolet-generated antigenic DNA

Genetics
It is typically believed that lupus is influenced by multiple genes. Lupus is usually influenced by gene polymorphisms, 30 of which have now been linked with the disorder. Some of these polymorphisms have been linked very tentatively, however, as the role that they play or the degree to which they influence the disease is unknown.