Overview
Common variable immunodeficiency, also called CVID, is an immune system disorder that causes low levels of the proteins in the body that help fight infections. People with CVID have repeated infections in the ears, sinuses and the system for breathing, called the respiratory system.
There's also an increased risk of digestive disorders, autoimmune disorders, blood disorders and cancer. CVID can be passed through families, called inherited.
Symptoms
How bad symptoms are varies greatly between people with CVID. Symptoms of common variable immunodeficiency may appear during childhood or the teen years. But many people don't get symptoms until they're adults.
If you have CVID, you'll likely have repeated infections before being diagnosed. The most common types of infections include pneumonia, sinusitis, ear infections and gastrointestinal infections.
Causes
In most CVID cases, the cause is unknown. In around 10% of people with CVID, a gene change has been found. Researchers believe that the condition is caused by a mix of factors in the environment and in genes. As of now, the environmental factors are unclear.