The lymphatic system is quite complex, but for the purposes of helping your hangover, the anatomy is pretty simple: Lymph is filled with proteins and disease-fighting cells that help the body eliminate waste, excess fluid, and damaged cells, according to the Cleveland Clinic. When you’re dealing with foreign bodies (like bacteria, viruses, and cancer cells), your immune system fights back by moving lymph through small bean-shaped glands throughout your body, called lymph nodes, that cleanse the lymph and eliminate infection, Cleveland Clinic says.
Drinking alcohol causes your blood vessels to expand (which the Mayo Clinic lists as a likely cause of headaches), and this expansion “increases the flow of lymph and the amount of fluid accumulating in your body’s tissues,” Dr. Clark says. This gives your lymphatic system more work to do and essentially puts extra stress on your body. “The lymphatic system is responsible for clearing out that excess fluid,” Dr. Clark explains. Exercise is the easiest way to stimulate the processing of lymph fluid, Dr. Clark says, adding that it can help alleviate hangover symptoms like headache and water retention.
If you’re reeling from a hangover, intense exercises might sound impossible, so Dr. Clark suggests a short leisurely walk to move without exacerbating your symptoms. “As with most of our biological processes, the overload of the system takes time to process,” he says. So even though you don’t feel that great, going for a walk can help your muscles contract and encourage regular lymphatic function. Additionally, Dr. Clark says that walking increases blood flow which helps your liver and kidneys process alcohol body faster than if you were resting.