Lymph is a clear fluid found throughout the lymphatic system in the human body. It is comprised of white blood cells and fluid from the intestines that contains fats and proteins from the food humans consume.
Lymph also comes from blood vessels that flow through the body. Each blood vessel pushes blood and blood plasma through the body. As the blood and blood plasma flow through these vessels, some of the watery blood plasma leaks into the tissues. This watery liquid is full of oxygen, proteins, white blood cells and glucose. It is eventually circulated into the lymphatic system and becomes a part of the lymph.