The immune system is comprised of the skin, the bloodstream (white blood cells), thymus (T cells and B cells), lymphatic system (lymoh nodes), spleen, and mucosal tissues (respiratory tract and gut.

These components help to prevent or limit infection. Each component and cells play a unique role, with different ways of recognizing problems, communicating with other cells, and performing their functions.

However, the immune system itself can fail and lead to Immune system disorders cause abnormally low activity or over activity of the immune system. In cases of immune system over activity, the body attacks and damages its own tissues (autoimmune diseases). Immune deficiency diseases decrease the body’s ability to fight invaders, causing vulnerability to infections.

Immune system disorders may either be abnormally low (under-active) or abnormally high (over-active). When the immune system fails, it is known as immunocompromise and will make the person vulnerable to viral, bacterial or fungal infections.

Infection in an immunocompromised patient is even more dangerous and worse. There are several disorders that shows an under-active immune system, and it includes:

  • Immune deficiencies. Is a condition wherein there is a defect in the immune system. It may be caused by an organism, like influenza virus, which are temporary disorders, or it can be inherited, like the Primary Immune deficiencies (PIDDs) which are permanent. Symptoms and treatment depends on the type of immune deficiency the person contracts.
  • Acquired Immune Deficiency Syndrome (AIDS). This is the infection with the Human Immunodeficiency Virus (HIV) that destroys the helper T cells, an important protective cells in the body, and deteriorates the immune system and the ability of the body to defend it. This condition is frequently sexually transmitted, but it can also be contracted through puncture of needles used by infected patients. Early in the infection, symptoms of HIV infection is not present, when symptoms does show, it appears like a flu that lasts for 4 to 8 weeks, symptoms may include fever, headache, feeling very tired (fatigue), and swollen glands (lymphadenopathy), then it would disappear for months to ten years. By this time HIV destroys T cells , and eventually result in symptoms such as recurring fever, swollen glands, fatigue, weight loss, and yeast infection. These symptoms may indicate that infection has progressed into a full-blown AIDS infection. Treatment for HIV infection starts with prevention, then drugs like the Nucleoside Reverse Transcriptase inhibitors (NRTIs), the Non-nucleoside-reverse transcriptase inhibitors (NNRTIs) and Protease Inhibitors are used to prevent progression to AIDs. As of the moment, there is still no cure to AIDs.
  • Severe Combined Immunodeficiency (SCID). This inherited disorder is characterized by having little or no immune system. This present as recurrent infections that are life-threatening, and other infections. Treatment for this disorder includes bone marrow transplant and intravenous immunoglobulin (IV Ig)

The other type of immune system disorder, the over-active immune system, includes the following disorders:

  • Allergy. This disorder is the over-reaction to a particular substance or allergen. This is common and has a varitey of types, such as food allergy, respiratory allergy and skin allergy. When people who are allergic to a particular allergen is exposed, his immune system will release the chemical, histamine, and cause the symptoms characteristic to allergy, such as swelling, inflammaion, and itching. Allergy treatment depends on the symptoms, usually it is done using anti-histamine drugs, or emergency treatment for severe reactions.
  • Asthma. This is an ongoing, long-lasting lung disease that manifests as attacks of difficulty with breathing. This condition can be associated with allergies. The symptoms characteristic for asthma are shortness of breath and wheezing, a whistling sound created when the patient inhales. Doctors use drugs to control the symptoms and the frequency of asthma, because there is no cure for asthma.
  • Eczema. This is chronic condition of the skin is characterized by itching, inflammation. Redness, and swelling of the skin. This is also triggered by a certain substance. Treatment begins with the prevention of flare-ups and hydrocortisone creams.
  • Anaphylaxis. This is the more severe form of allergic reaction, that manifests as shortness of breath, wheezing, difficulty of breathing, and difficulty of swallowing or speaking due to swelling of the throat, tongue, or windpipe. This is treated by injection with epinephrine, anti-histamines and steroids.
  • Autoimmunity. This is a response to an unknown trigger, that caused the immune system to produce antibodies that instead of fighting infections, attack the body’s own tissues. There are several types of autoimmune disease and treatment generally focuses on reducing immune system activity. Examples of autoimmune diseases include:
    • Rheumatoid arthritis. The immune system produces antibodies that attach to the linings of joints. Immune system cells then attack the joints, causing inflammation, swelling, and pain.
    • Systemic lupus erythematosus (lupus). People with lupus develop autoimmune antibodies that can attach to tissues throughout the body. The joints, lungs, blood cells, nerves, and kidneys are commonly affected in lupus.
    • Inflammatory bowel disease (IBD). The immune system attacks the lining of the intestines, causing episodes of diarrhea, rectal bleeding, urgent bowel movements, abdominal pain, fever, and weight loss. Ulcerative colitis and Crohn’s disease are the two major forms of IBD.
    • Multiple sclerosis (MS). The immune system attacks nerve cells, causing symptoms that can include pain, blindness, weakness, poor coordination, and muscle spasms.
    • Type 1 diabetes mellitus. Immune system antibodies attack and destroy insulin-producing cells in the pancreas.
    • Guillain-Barre syndrome. The immune system attacks the nerves controlling muscles in the legs and sometimes the arms and upper body. Weakness results, which can sometimes be severe.
    • Psoriasis. In psoriasis, overactive immune system blood cells called T-cells collect in the skin. The immune system activity stimulates skin cells to reproduce rapidly, producing silvery, scaly plaques on the skin.
    • Graves’ disease. The immune system produces antibodies that stimulate the thyroid gland to release excess amounts of thyroid hormone into the blood (hyperthyroidism). Symptoms of Graves’ disease can include bulging eyes as well as weight loss, nervousness, irritability, rapid heart rate, weakness, and brittle hair.
    • Hashimoto’s thyroiditis. Antibodies produced by the immune system attack the thyroid gland, slowly destroying the cells that produce thyroid hormone. Low levels of thyroid hormone develop (hypothyroidism), usually over months to years. Symptoms include fatigue, constipation, weight gain, depression, dry skin, and sensitivity to cold.
    • Myasthenia gravis. Antibodies bind to nerves and make them unable to stimulate muscles properly. Weakness that gets worse with activity is the main symptom of myasthenia gravis.
    • Vasculitis. The immune system attacks and damages blood vessels in this group of autoimmune diseases. Vasculitis can affect any organ, so symptoms vary widely and can occur almost anywhere in the body.


Diagnosis depends on the type of immune system disorder. Generally, patients suspected to have these disorders should consult a medical practitioner and ask to be screened.



See Types and Symptoms section.

Related Articles


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Referred pain is a phenomenon where pain is perceived at a [...]


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Quinoline yellow is a synthetic food colorant commonly used in the [...]


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Pneumothorax is a condition characterized by the presence of air in [...]