Immune System Disorders and Diseases

Immune system disorders are conditions in which the immune system doesn't work as it should. The immune system is responsible for protecting the body against viruses, bacteria, and other invaders.

Immune system disorders can be characterized by a weakened immune system or autoimmune diseases, in which the immune system mistakenly attacks the body's healthy cells. There are over 100 types of autoimmune diseases and approximately 80% of all people diagnosed with these conditions are female.

There are different ways that immune system disorders can develop. Some people are born with a weak immune system, while others have an overactive immune system that reacts to substances that are normally harmless, as in some forms of asthma and eczema.

Immune System Disorders: Primary and Secondary Immune Deficiency

Primary immune deficiency disorders are present at birth. They cause a weakened immune system and are often inherited. The diagnoses can be made months after birth or many years later.

These disorders can be triggered by a single gene defect. There are more than 200 different forms of primary immune deficiency disorders, and they affect approximately 500,000 people in the United States.

People with primary immune deficiency disorders can sometimes have a weak response to vaccines and an increased risk of developing autoimmune disorders and malignancy.

Severe combined immunodeficiency (SCID), also called bubble boy disease, is an example of a primary immune deficiency. Children with this condition are missing important white blood cells.

Secondary immune deficiency refers to diseases that people can get later in life that weaken their immune systems. AIDS (acquired immune deficiency syndrome) caused by an HIV infection is one example. Without treatment, HIV infection can cause severe damage to the immune system, leaving the body vulnerable to infections.

Overactive Immune System Examples

An overactive immune system may react to allergens (harmless elements) like dust, mold, pollen, and foods. in these cases, your body can't tell the difference between your healthy, normal cells and invaders.

Allergies and Asthma

An overactive immune system will react to allergens like dust, mold, pollen, and foods.

Asthma is one of the most common conditions associated with an overactive immune system. When you have asthma, an immune response in your lungs can lead to wheezing, coughing, and shortness of breath.

Eczema (itchy skin is triggered by an allergen) and hay fever (seasonal allergies, also known as allergic rhinitis) are other examples. Seasonal allergens can trigger itchy/watery eyes and a runny nose.

Autoimmune Conditions

When you have an autoimmune condition, your body attacks itself because it can't tell the difference between your healthy, normal cells and invaders.

Common Autoimmune Diseases and Symptoms

Autoimmune diseases cause the immune system to attack healthy cells in the body. They are chronic conditions that require ongoing treatment. They usually do not have a cure.

The cause is unknown. It has been hypothesized that they are caused by a combination of genetic predisposition and environmental triggers. Different autoimmune diseases affect the body in different ways and cause different symptoms.

Type 1 Diabetes

Type 1 diabetes is caused by an autoimmune process in the body that mistakenly destroys the beta cells of the pancreas, which are the insulin-producing cells.

It affects people who are genetically predisposed to the condition. It's found in 5% to 10% of people who have any type of diabetes.

It can appear at any stage of life, but it is the most common type of diabetes in children, teens, and young adults.

Symptoms include:

• Excessive thirst
• Excessive urination
• Sudden weight loss
• Tiredness and weakness
• Blurred vision
• Slower wound healing
• Mood swings

Children and teenagers who have type 1 diabetes are more likely to develop other autoimmune diseases, like thyroid disorders or celiac disease. 

Rheumatoid Arthritis

In rheumatoid arthritis (RA), the immune system attacks healthy cells, resulting in inflammation in different parts of the body. It commonly affects joints in the hands, wrists, and knees.

RA can begin at any age, and it is more common between 45 and 60 years old. Women have a higher chance of developing the disease and experiencing more severe pain from the condition.

Symptoms include:

• Pain or aching in more than one joint
• Stiffness in more than one joint
• Tenderness and swelling in more than one joint
• Similar symptoms on both sides of the body (such as in both hands or both knees)
• Weight loss
• Fever
• Fatigue or tiredness
• Weakness

Psoriatic Arthritis

Psoriatic arthritis (PsA) is a form of chronic inflammatory arthritis that is present in nearly 30% of people who have psoriasis. It can also affect people without psoriasis.

The disease affects the joints and skin—mainly large joints of the lower extremities, distal joints of the fingers and toes, joints in the back, and sacroiliac joints of the pelvis.

This condition often begins between ages 30 and 50 years. For many people with psoriasis, PsA starts about 10 years after psoriasis develops.

PsA can be mild with occasional flare-ups, or it can be continuous and cause joint damage if it is not treated. 

The most common symptoms are:

• Joint pain and stiffness 
• Swelling of the fingers and toes 
• Skin lesions 
• Nail deformity 
• Back pain

Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system that affects the brain, optic nerves, and/or spinal cord.

This condition damages the myelin sheath, which is the material that surrounds and protects nerve cells. This damage slows down or blocks messages between the brain and body.

Although it is not inherited, people with a family history of this condition are more susceptible to the disease. The first signs of MS often appear between 20 and 40 years old. Multiple sclerosis affects women more than men.

MS symptoms often include:

• Vision problems, such as blurred or double vision, or optic neuritis, which causes a rapid loss of vision
• Muscle weakness, often in the hands and legs, and muscle stiffness accompanied by painful muscle spasms
• Tingling, numbness, or pain in the arms, legs, trunk, or face
• Clumsiness, particularly when walking
• Bladder control problems
• Dizziness

Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) can affect any organ in the body and encompass a wide spectrum of severity. It can cause mild symptoms, such as skin rash, or severe complications, like heart problems.

It tends to run in families, and it affects women more than men.

The most common symptoms of lupus are:

• Severe fatigue
• Joint pain and swelling
• Headaches
• Butterfly rash on the cheeks and nose
• Hair loss
• Anemia
• Problems with blood-clotting
• Raynaud's phenomenon

Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) refers to a group of disorders that cause chronic inflammation of the digestive tract. Two of the most common forms of IBD are Crohn's disease and ulcerative colitis. Approximately 1.5 million people in the United States have either Crohn’s disease or ulcerative colitis.

• Crohn's disease is an illness in which the intestine becomes inflamed and ulcerated (marked with sores). Crohn's disease usually affects the lower part of the small intestine, but it can occur in any part of the large or small intestine, stomach, esophagus, or even the mouth. It is most common between the ages of 15 and 30.
• Ulcerative colitis is a chronic inflammatory disease that affects the lining of the colon (large intestine) and rectum. People with this condition have tiny ulcers and small abscesses in their colon and rectum that flare up every so often and cause bloody stools and diarrhea.

Frequent symptoms include:

• Abdominal pain
• Fatigue
• Cramping
• Persistent diarrhea
• Bloody stools
• Lack of appetite
• Weight loss
• Anemia

Addison's Disease

Addison's disease, also known as adrenal insufficiency, affects the function of the adrenal glands, which are small hormone-producing glands located on top of each kidney. It is a rare disorder in which the body doesn't produce enough adrenal hormones.

Addison’s disease affects 1 in 100,000 people and affects men and women equally. It runs in families, and people first notice symptoms between ages 30 and 50 years old. Diagnosis is often delayed because it is a rare disease and the symptoms are nonspecific and can come and go.

Some of the symptoms include:

• Abdominal pain
• Abnormal menstrual periods
• Craving for salty food
• Dehydration
• Depression
• Diarrhea
• Irritability
• Lightheadedness or dizziness when standing up
• Loss of appetite
• Low blood glucose
• Low blood pressure
• Muscle weakness
• Nausea
• Patches of dark skin, especially around scars, skin folds, and joints
• Sensitivity to cold
• Unexplained weight loss
• Vomiting
• Worsening fatigue (extreme tiredness)

Graves Disease

Graves disease is an autoimmune disorder that causes hyperthyroidism (an overactive thyroid).

With Grave's disease, the immune system overstimulates the thyroid and causes it to make more thyroid hormone than your body needs. Excess thyroid hormones can cause a variety of problems. 

Graves disease affects about 1 in 200 people. It is the leading cause of hyperthyroidism in the United States. Women have higher chances of developing the disease.

The condition can trigger many symptoms, including:

• Weight loss
• Heart palpitations
• Fatigue
• Muscle weakness
• Agitation
• Irritability
• Insomnia
• Increased sweating/heat intolerance
• Shaking hands
• Diarrhea or frequent bowel movements
• Increased appetite (sometimes a decrease instead)
• Thinning hair
• Shortness of breath
• Fertility problems
• Menstrual-cycle changes
• Dizziness
• Hypertension (high blood pressure)

Sjögren's Syndrome

Sjögren's syndrome affects the salivary and tear glands, and people with this disease will often complain about dry mouth and dry eyes. It can also affect the joints, nose, skin, and other body parts that need moisture, including the lungs, kidneys, blood vessels, digestive organs, and nerves.

Sjögren's syndrome primarily affects women age 40 and older. It is estimated that between 400,000 and 3.1 million adults have Sjögren's syndrome. It is sometimes linked to RA and lupus.

Hashimoto's Disease

Hashimoto's disease is a type of hypothyroidism (underactive thyroid) and is at least eight times more common in women than men. With this condition, the immune system attacks the thyroid, damaging it so it can't make enough thyroid hormones.

Hashimoto’s disease is common and affects about five people in 100 in the United States. It commonly appears between ages 30 to 50 and tends to run in families. People with other autoimmune diseases are also more likely to have this condition.

The most common symptoms are:

• Fatigue
• Sudden weight gain
• Joint and muscle pain
• Thinning hair
• Irregular menstrual periods
• Sudden weight gain
• Depression
• Memory problems

Celiac Disease

Celiac disease is an autoimmune disorder in which the ingestion of gluten triggers the immune system to damage the small intestines. It often impairs nutrient absorption.

The condition is estimated to affect 1 in 100 people worldwide. Celiac disease runs in families, and people who have a first-degree relative with celiac disease (parent, child, sibling) have a one-in-10 risk of developing this condition. It can develop at any age.

Frequent symptoms are:

• Digestive problems
• Diarrhea
• Abdominal pain
• Nausea
• Weight loss
• Constipation
• Tiredness
• Unexplained anemia
• Musculoskeletal problems
• Blistering skin rash

Autoimmune Disease Risk Factors

Many factors can increase the risk of autoimmune disease: heredity, genetics, and environmental triggers. The conditions are prevalent in women and researchers don't have a consensus to explain why women are more vulnerable.

Diagnostic Tests

Diagnosis of immune-related problems can be tricky. In some cases, symptoms might be subtle, and they may wax and wane with time. Some immune-related problems also have similar, overlapping symptoms. 

For many immune-related problems, there isn’t one single test that can prove that you have the condition. Instead, your clinician pulls together the clinical picture from your symptoms, your medical history, your exam, and related tests. Sometimes these diseases can only be diagnosed after ruling out other potential causes.

The tests needed will depend upon your symptoms and your overall medical picture. Some potential tests might include:

• Complete blood count (CBC): General test that can show potential inflammation, infection, and possible atopic immune problems.
• C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR): Both may signal increased inflammation
• Complement tests: These tests may offer clues about primary immune deficiencies, infection, or autoimmune conditions.
• Allergy tests
• Genetic tests These are used for primary immune disorders.

If autoimmune disease is suspected, your healthcare provider might recommend tests for antibodies your body has made against itself. For example, your healthcare provider might recommend a rheumatoid factor test if your symptoms indicate you might have rheumatoid arthritis. But this test is sometimes positive in other autoimmune conditions as well.

One initial screening test is antinuclear antibody (ANA), which may be positive in several different autoimmune conditions.

If that is positive, your clinician might recommend additional antibody tests, depending on the clinical picture. Depending on the context, you might need imaging tests or other assessments, like X-rays, biopsies (taking samples of tissue for testing in a lab), or magnetic resonance imaging (MRI). 

When to Seek Medical Attention

If something seems off in your body, trust your instincts and get it checked out. If you have new symptoms, like increased fatigue and joint pain, don't hesitate to get an assessment. You are the person who knows your body best. 

For symptoms that might indicate an infection, like fever, see a healthcare provider promptly. For any life-threatening symptoms, like sudden difficulty breathing, call 911. 

A Word From Verywell 

The journey to a diagnosis of autoimmune disease can be long and stressful. The symptoms of autoimmune diseases are often nonspecific and episodic. It is important for you to tell your healthcare provider about any new symptoms you are experiencing.

Although the conditions can't be cured, there are medications that can help alleviate symptoms and slow the progression of autoimmune diseases. Early treatment generally leads to better outcomes.