Autoimmune diseases are conditions in which your immune system mistakenly damages healthy cells in your body. Types include rheumatoid arthritis, Crohn’s disease, and some thyroid conditions.
Your immune system usually protects you from diseases and infections. When it senses these pathogens, it creates specific cells to target foreign cells.
Usually, your immune system can tell the difference between foreign cells and your cells.
But if you have an autoimmune disease, your immune system mistakes parts of your body, such as your joints or skin, as foreign. It releases proteins called autoantibodies that attack healthy cells.
Some autoimmune diseases target only one organ. Type 1 diabetes damages your pancreas. Other conditions, such as systemic lupus erythematosus, or lupus, can affect your whole body.
Below we provide an overview of some of the most common autoimmune diseases.
What can cause autoimmune disease?
Doctors don’t know exactly what causes the immune system to misfire. Yet some people are more likely to get an autoimmune disease than others.
Some factors that may increase your risk of developing an autoimmune disease can include:
Your sex: People assigned female at birth between the age of 15 and 44 are more likely to get an autoimmune disease than people assigned male at birth.
Your family history: You may be more likely to develop autoimmune diseases due to inherited genes, though environmental factors may also contribute.
Environmental factors: Exposure to sunlight, mercury, chemicals like solvents or those used in agriculture, cigarette smoke, or certain bacterial and viral infections, including COVID-19Trusted Source, may increase your risk of autoimmune disease.
Ethnicity: Some autoimmune diseases are more common in people in certain groups. For example, White people from Europe and the United States may be more likely to develop autoimmune muscle disease, while lupus tends to occur more in people who are African American, Hispanic, or Latino.
Nutrition: Your diet and nutrients may impact the risk and severity of autoimmune disease.
Other health conditions: Certain health conditions, including obesity and other autoimmune diseases, may make you more likely to develop an autoimmune disease.
What are the common symptoms of an autoimmune disease?
Different autoimmune diseases may have similar early symptoms. These can include:
fatigue
dizziness or lightheadedness
low grade fever
muscle aches
swelling
trouble concentrating
numbness and tingling in your hands and feet
hair loss
skin rash
With some autoimmune diseases, including psoriasis or rheumatoid arthritis (RA), symptoms may come and go. A period of symptoms is called a flare up. A period when the symptoms go away is called remission.
Individual autoimmune diseases can also have their own unique symptoms depending on the body systems affected. For example, with type 1 diabetes, you may experience extreme thirst and weight loss. Inflammatory bowel disease (IBD) may cause bloating and diarrhea.
What are the most common autoimmune diseases?
Researchers have identified more than 100 autoimmune diseases. Here are 14 more common ones.
1. Type 1 diabetes
Your pancreas produces the hormone insulin, which helps regulate blood sugar levels. In type 1 diabetes, the immune system destroys insulin-producing cells in your pancreas.
High blood sugar from type 1 diabetes can damage the blood vessels and organs. This can include your:
heart
kidneys
eyes
nerves
2. Rheumatoid arthritis (RA)
In RA, your immune system attacks the joints. This causes symptoms affecting the joints such as:
swelling
warmth
soreness
stiffness
While RA more commonly affects people as they get older, it can also start as early as your 30s. A related condition, juvenile idiopathic arthritis, can start in childhood.
3. Psoriasis/psoriatic arthritis
Skin cells grow and then shed when they’re no longer needed. Psoriasis causes skin cells to multiply too quickly. The extra cells build up and form inflamed patches. On lighter skin tones, patches may appear red with silver-white scales of plaque. On darker skin tones, psoriasis may appear purplish or dark brown with gray scales.
Up to 30%Trusted Source of people with psoriasis also develop psoriatic arthritis. This can cause joint symptoms that include:
swelling
stiffness
pain
4. Multiple sclerosis
Multiple sclerosis (MS) damages the protective coating surrounding nerve cells (myelin sheath) in your central nervous system. Damage to the myelin sheath slows the transmission speed of messages between your brain and spinal cord to and from the rest of your body.
This damage can lead to:
numbness
weakness
balance issues
trouble walking
Different forms of MS progress at different rates. Difficulties with walking are one of the most common mobility issues with MS.
Pernicious anemia
Pernicious anemia may happen when an autoimmune disorder causes your body to not produce enough of a substance called intrinsic factor. Having a deficiency in this substance reduces the amount of vitamin B12 your small intestine absorbs from food. It can cause a low red blood cell count.
Without enough of this vitamin, you’ll develop anemia, and your body’s ability for proper DNA synthesis will be altered.
It can cause symptoms that include:
fatigue
weakness
headaches
This rare autoimmune disease typically occurs in people ages 60 to 70 and older.
