Soldiers may also elect not to wear a combat patch. Controversies have arisen in recent years over brigade commanders' decisions to ban combat patches in certain situations. This has been done in an effort to make new recruits, who didn't have the patches, feel less excluded.
Cortisol and Stress: How Cortisol Levels Affect the Body. Cortisol and stress are connected and, although stress isn't the only reason for the release of cortisol into the blood stream, it is still known as a stress hormone. Every time that you are confronted with a stressful situation your body undergoes a fight or flight response and cortisol levels increase.
Stress hormones like adrenaline and cortisol have effects on the nervous, endocrine and immune systems of the body. It is thought that adrenaline and cortisol suppress the natural killer cells function and reduce their ability to assess the body for abnormal cells, making people more susceptible to viral infections.