Overview
An immune deficiency means the immune system is not protecting the body effectively against germs such as bacteria, viruses, fungi, or parasites. This can make a person more likely to get repeated infections, infections that are unusually severe, or infections that take longer than expected to improve. Immune deficiencies can be primary, meaning they are usually caused by inherited genetic changes, or secondary, meaning they happen because of another condition or exposure.
Key Symptoms
Symptoms often relate to repeated infections, such as frequent ear infections, sinus infections, pneumonia, skin infections, or diarrhea. Infections may be unusually severe, keep coming back, or be caused by uncommon germs. Some people also have poor growth, weight loss, ongoing tiredness, mouth thrush, or slow healing.
Causes and Risk Factors
Primary immune deficiencies are usually caused by inherited problems in parts of the immune system. Secondary immune deficiencies can happen because of HIV infection, cancer, malnutrition, severe burns, aging, or loss of proteins from the body. They can also result from treatments that suppress immunity, such as chemotherapy, steroids, or medicines used after organ transplant or for autoimmune diseases.
Who Is Affected
Immune deficiencies can affect people of any age. Some inherited forms are noticed in infancy or childhood, while others are found later because symptoms are mild or delayed. Secondary immune deficiencies are common in adults and can occur anywhere in the world, especially where infections, poor nutrition, or limited access to healthcare are major concerns.
Prevention
Not all immune deficiencies can be prevented, especially inherited forms. However, reducing infection exposure, keeping up with recommended vaccines when appropriate, treating underlying illnesses, and avoiding unnecessary immune-suppressing medicines may help lower risk or reduce complications. People with weakened immunity should ask a healthcare professional which vaccines and preventive steps are suitable for them.
Diagnosis and Tests
Diagnosis starts with a careful history of infections, family history, medicines, and other medical conditions. Doctors may use blood tests to look at white blood cells, antibodies, and how well the immune system responds. Depending on the situation, testing may also include genetic tests, HIV testing, imaging, or evaluation by an immunology specialist.
Treatment Categories
Treatment depends on the type and cause of the immune deficiency. It may include prompt treatment of infections, preventive measures to reduce infections, treatment of an underlying illness, or changing medicines that are weakening immunity when possible. Some people need specialized treatments such as antibody replacement or other immune-based care directed by a specialist.
Living With It
Living with an immune deficiency often involves planning ahead for infections and staying in regular contact with healthcare providers. Keeping records of infections, hospital visits, vaccines, and medicines can be helpful. Emotional stress, school absences, and work disruptions are also common, so support from family, community, and care teams can matter.
When to Seek Medical Care
Seek medical care if you or your child has frequent infections, infections that are severe or unusual, poor growth, unexplained weight loss, or infections that keep returning after treatment. It is also important to get checked if you have a known condition or take medicines that can weaken the immune system and you develop signs of infection. Early assessment can help identify the cause and reduce complications.
When It May Be an Emergency
Get urgent medical help for trouble breathing, chest pain, confusion, severe weakness, high fever with a very ill appearance, dehydration, seizures, or signs of sepsis such as fast breathing, fast heart rate, and extreme sleepiness. People with known immune deficiency may become seriously ill from infections more quickly than others. If a baby, child, or adult with possible immune deficiency looks very unwell, seek emergency care right away.