Jet lag, Melatonin and Diving


Long-distance air travel crossing several time zones in a short time causes jet lag syndrome (also called Rapid Time Zone Change Syndrome) upon arrival, because our circadian rhythm established at our origin is out of sync with the day-night cycle at our destination. Symptoms include feeling sleepy, hungry and alert at the wrong times. This affects our social life and ability to work or exercise. Fortunately within days our internal clock synchronizes with the environment. The more time zones we cross, the greater the expression of the syndrome and the longer it takes to overcome.

Divers often travel to faraway dive locations and may be affected by jet lag for the better part of their trip. The jet lag may affect one’s ability to dive safely; therefore, divers need to know how to minimize its effects.


Deep Vein Thrombosis (DVT)

blood clotDeep vein thrombosis (DVT) is a condition in which a blood clot (thrombus) forms in one or more of the deep veins, usually in the legs. Blood clots can break free and travel with blood causing life-threatening condition like pulmonary embolism (PE) or a stroke due to paradoxical embolism in people with patent foramen ovale (PFO). DVT is not related to diving, but divers often travel and thus are exposed to risk of DVT. In case of acute DVT, divers must not dive.