Immune system disorder causes the immune system to act abnormally — either more than usual or less than usual. In case the immune system is acting more than it is supposed to, it identifies tissues of the body as external bodies and attacks them. Immune system deficiency, on the other hand, causes a drop in the ability of the body to fight external bodies, thereby resulting in exposure to infections.

There are numerous types of immune system disorders, which include rheumatoid arthritis, systemic lupus erythematosus, inflammatory bowel disease (IBD), multiple sclerosis, type 1 diabetes mellitus, psoriasis, and various others. The type depends on the area of the body where the immune system attacks and the nature of the attack.

Symptoms

The symptoms of immune system disorder allow us to understand the disorder in the initial stages as the signs are fairly straight-forward. One can experience any of the following symptoms at the onset of this disorder:

• Fatigue
• Muscle ache
• Redness of the skin and swelling
• Mild fever
• Difficulty in concentrating
• Numbness in the hands and feet and a tingling sensation
• Loss of hair
• Rashes on the skin

Apart from these, the different types of immune system disorders can have their own symptoms.

Symptoms associated with some immune system disorders might not be constant and are experienced in shorter durations. In such cases, symptoms showing up for a particular duration are known as flare-ups, while the period during which the symptoms go away is known as remission. This means that even if symptoms like fatigue, muscle ache, and swelling come and go, they can still be signs of immune system disorder.

Causes

While the exact cause of the immune system disorder is not yet known, some theorists believe that certain microorganisms cause changes that bring about confusion in the immune system. Essentially, in the case of an immune system disorder, the immune system of a body is not able to differentiate between the healthy tissue that is a part of the body and harmful antigens. Thus, it receives a signal that triggers the destruction of useful tissues. Genes are considered to be one of the main reasons for having an immune system disorder.

Risk factors

Some of the risk factors that lead to an immune system disorder include:

• Gender
  Females are at a higher risk of getting immune system disorder. Three out of four cases of immune system disorder are of women.
• Age
  Young and middle-aged people are at a greater risk of being diagnosed with this condition.
• Ethnicity
  Some ethnicities are at greater risk; these include African American, American Indian, and Latino.
• Family history
  People with a family history of immune system disorder are more likely to get it.
• Previous infection
  If you’ve previously had a bacterial or viral infection, there are greater chances of developing an immune system disorder.
• External agents
  Exposure to certain external agents like some medications may increase the chances of developing an immune system disorder.