What is lupus?

Systemic lupus erythematosus is a disease in which the immune system mistakenly attacks healthy tissue. The resulting inflammation can cause pain and damage in almost any part of the body.

Lupus affects each person differently. Most people experience episodes of disease activity (flares), followed by periods with no symptoms.

The Lupus Foundation of America estimates that more than 1.5 million Americans are living with lupus. There are more than 16,000 new cases diagnosed each year. Worldwide, there may be as many as 5 million people with lupus. Anyone can get this disease, but it’s most likely to appear in women between the ages of 15 and 44.

There’s a huge variation in symptoms from person to person. Symptoms can come and go, and they range from very mild to quite severe. While some symptoms can disappear and never return, others can become permanent.

Some of the most common symptoms include:

  • dry eyes
  • mouth ulcers
  • fatigue
  • fever
  • loss of appetite, nausea, vomiting, diarrhea, and weight loss
  • shortness of breath
  • joint inflammation, stiffness, and pain
  • swollen glands
  • muscle pain
  • chest pain when you take a deep breath
  • hair loss
  • sun sensitivity

One of the more obvious symptoms of lupus is a butterfly-shaped rash on the face. The rash appears on the bridge of the nose and spreads out over the cheeks.

Some people with lupus have Raynaud’s phenomenon, a condition that causes your fingers and toes to turn blue or white when you’re cold or stressed.

Early warning signs of an impending flare include increasing fatigue, rash, and fever.

As lupus progresses, inflammation can damage tissue and organs throughout the body.

Lupus can produce changes in your behavior if it causes inflammation in your brain or central nervous system. It can affect your memory, making it difficult to express yourself. It can even lead to depression. In some cases, it can cause hallucinations.

Some people with lupus experience:

  • headaches
  • dizziness
  • problems with vision
  • seizures
  • strokes

Inflammation that occurs in the hearing nerve may result in hearing loss.

Lupus can cause inflammation in the heart, increasing the risk of heart disease and heart attack. Symptoms include chest pain and heart murmurs.

Inflammation in the lungs and chest cavity can make it painful to take a deep breath. Inflammation in the chest cavity lining is known as pleuritis. Lupus increases your risk for developing pneumonia.

According to the Lupus Foundation of America, about 40 percent of people with lupus will develop kidney problems, increasing their risk for kidney failure. Inflammation in the kidneys (lupus nephritis) can make it hard for your kidneys to filter waste and toxins from your body.

Symptoms of kidney damage include:

  • swelling (edema) of the legs, hands, or eyelids
  • puffiness
  • weight gain
  • dark or foamy urine

Lupus can affect your blood and blood vessels, increasing your risk of having:

  • a low number of healthy red blood cells (anemia)
  • a low number of white blood cells (leukopenia)
  • a low number of blood platelets (thrombocytopenia)
  • inflammation of the blood vessels (vasculitis)
  • bleeding
  • blood clots
  • hardening of the arteries

Some people with lupus also develop another immune disorder called Sjogren’s syndrome. Sjogren’s affects the body’s moisture-producing glands. Symptoms include chronically dry eyes and mouth. Sjogren’s can also cause:

  • swollen joints and glands
  • dry skin
  • vaginal dryness
  • a dry cough

With lupus, you’re more prone to all types of infection, increasing the risk of:

  • urinary tract infections
  • respiratory infections
  • salmonella infections
  • yeast infections
  • herpes
  • shingles

There’s a risk of bone tissue death (avascular necrosis) if lupus affects the blood supply to your bones. Symptoms include bone fractures and breaks, especially in the hips.

People with lupus may develop an overactive thyroid (hyperthyroidism) or underactive thyroid (hypothyroidism).

Lupus can also affect pregnancy, increasing the risk of complications like high blood pressure, miscarriage, and premature birth.

The exact cause of lupus isn’t clear. Some researchers theorize that it’s a combination of genetics and environmental or hormonal factors.

Lupus is a chronic disease with no known cure. However, there are many types of treatment, depending on how lupus affects you. With ongoing care, many people with lupus live full, active lives.