<p>Your endocrine system includes eight major glands throughout your body. These glands make <a href="https://medlineplus.gov/hormones.html">hormones</a>. Hormones are chemical messengers. They travel through your bloodstream to tissues or organs. Hormones work slowly and affect body processes from head to toe. These include:</p><ul> <li>Growth and development</li> <li>Metabolism - digestion, elimination, breathing, blood circulation and maintaining body temperature </li> <li>Sexual function</li> <li>Reproduction</li> <li>Mood</li> </ul> <p>If your hormone levels are too high or too low, you may have a hormone disorder. Hormone diseases also occur if your body does not respond to hormones the way it is supposed to. Stress, infection and changes in your blood's <a href="https://medlineplus.gov/fluidandelectrolytebalance.html">fluid and electrolyte balance</a> can also influence hormone levels.</p> <p>In the United States, the most common endocrine disease is <a href="https://medlineplus.gov/diabetes.html">diabetes</a>. There are many others. They are usually treated by controlling how much hormone your body makes. Hormone supplements can help if the problem is too little of a hormone.</p>