Secondary immunodeficiency occurs when the immune system is weakened due to external factors rather than being inherited. This condition can result from various causes, including infections like HIV, certain medications such as chemotherapy, malnutrition, or chronic diseases like diabetes. Unlike primary immunodeficiencies, which are genetic, secondary immunodeficiencies can develop at any age. Individuals with this condition are more susceptible to infections and may experience more severe symptoms. Treatment often focuses on managing the underlying cause and may include medications, lifestyle changes, or therapies to boost the immune response.