Lupus is a chronic autoimmune disease in which the body's immune system becomes hyperactive and attacks normal, healthy tissue. This results in symptoms such as inflammation, swelling, and damage to joints, skin, kidneys, blood, the heart, and lungs. 2
Under normal function, the immune system makes proteins called antibodies in order to protect and fight against antigens such as viruses and bacteria.
Lupus makes the immune system unable to differentiate between antigens (a substance capable of inducing a specific immune response) and healthy tissue. This leads the immune system to direct antibodies against the healthy tissue - not just antigens - causing swelling, pain, and tissue damage.
Any part of the body can be affected by lupus as it has an array of clinical manifestations affecting the skin, joints, brain, lungs, kidneys, blood vessels and other internal organs.1
This information hub offers detailed but easy-to-follow information about lupus. Should you be interested in the latest scientific research on lupus, please see our lupus news section.
Fast facts on lupus
Here are some key points about lupus. More detail and supporting information is in the main article.
Several different kinds of lupus have been identified, but the type that we refer to simply as lupus is known as systemic lupus erythematosus or SLE. Other types include discoid (cutaneous), drug-induced, and neonatal.
Patients with discoid lupus have a version of the disease that is limited to the skin. It is characterized by a rash that appears on the face, neck, and scalp, and it does not affect internal organs. Less than 10% of patients with discoid lupus progress into the systemic form of the disease, but there is no way to predict or prevent the path of the disease.
SLE is more severe than discoid lupus because it can affect any of the body's organs or organ systems. Some people may present inflammation or other problems with only skin and joints, while other SLE sufferers will see joints, lungs, kidneys, blood, and/or the heart affected. This type of lupus is also often characterized by periods of flare (when the disease is active) and periods of remission (when the disease is dormant).
Drug-induced lupus is caused by a reaction with certain prescription drugs and causes symptoms very similar to SLE. The drugs most commonly associated with this form of lupus are a hypertension medication called hydralazine and a heart arrhythmia medication called procainamide, but there are some 400 other drugs that can also cause the condition. Drug-induced lupus is known to subside after the patient stops taking the triggering medication.
A rare condition, neonatal lupus occurs when a mother passes autoantibodies to a fetus. The unborn and newborn child can have skin rashes and other complications with the heart and blood. Usually a rash appears but eventually fades within the first six months of the child's life.
You can learn more about the different types of lupus on our types of lupus page.
The normal function of the immune system is to protect and fight off viruses, bacteria and germs by producing proteins called antibodies that are produced by white blood cells (B lymphocytes).
With lupus, the immune system malfunctions and cannot distinguish between foreign invaders and healthy tissue. Antibodies are then produced against the body's healthy cells and tissues, causing inflammation, pain and damage in various parts of the body.1,10
These antibodies, called autoantibodies, contribute to the inflammation of numerous parts of the body and can cause damage to organs and tissues. The most common type of autoantibody that develops in people with lupus is called an antinuclear antibody (ANA) because it reacts with parts of the cell's nucleus (command center).
The autoantibodies circulate in the blood, but some of the body's cells have walls permeable enough to let some autoantibodies through. These can then attack the DNA in the cell's nucleus. This is why some organs can be attacked during a flare-up while others are not.12
It is important to note that lupus is not a contagious disease.
Lupus is a disease of flare-ups and remissions. Symptoms of the chronic condition can exacerbate, making the patient feel ill, before a period of symptom improvement occurs.
Based on the results of a survey from the Lupus Foundation of America, around 72% of Americans aged 18-34 have either not heard of the disease or know nothing about it other than the name, despite this age group being at greatest risk for the condition.
Lupus gained more attention from the public in 2015 after singer Selena Gomez announced she had been diagnosed with the condition in her late teens and underwent treatment for the disease.
We discussed all of this in our October 2015 feature, Lupus: a serious disease we know little about.
Follow us to the next page where we look at the causes of lupus. Alternatively, read all about the types of lupus and the risk factors, symptoms and diagnosis or the available options for treating and managing lupus.