"I'm healthy, but why do I get sick so often?" may be a question many people ask themselves. Surely you have met someone who gets sick often (or you are yourself). There are several reasons why this happens.

Some individuals are thought to be resistant to certain bacterial and viral infections. "Immunologists refer to them as 'super-immunity' and their genetic makeup is the focus of a whole field of research," he told Health. Holly Phillips, doctor.

Immunity is determined by several factors. Genetics plays a big role. Immune genes are numerous and complex and your immune response depends on their performance.

Experts also believe that you develop immunity when you are young, or perhaps even before you are born. "There are factors during infancy and childhood, and perhaps even in the womb, that contribute to the development of the immune system, but they are not fully understood.

Moreover, environmental factors, such as pollutants and toxins, can also weaken the immune system over time. Lifestyle factors, including stress, obesity, alcohol consumption and poor hygiene, can all weaken the immune response and lead to more frequent infections.

How can you strengthen your immune system?

1. Diet: fruits, vegetables and other foods that contain zinc, iron, vitamin C, omega-3 fatty acids.

2. Sleep and physical activity: increase blood circulation which stimulates the production of antibodies.