Would you like to get rid of jet lag?

Jet lag, also called jet lag disorder, is a temporary sleep problem that can affect anyone who quickly travels across multiple time zones.

Your body has its own internal clock, or circadian rhythms, that signals the body when to stay awake and when to sleep. Jet lag occurs because your body's clock is still following your original time zone, instead of the time zone where you have traveled. The more time zones crossed, the more likely you are to experience jet lag.

Jet lag can cause daytime fatigue, an unpleasant feeling, difficulty staying alert and gastrointestinal problems. Jet lag is temporary, but it can significantly reduce your daily activities. Fortunately there are steps you can take to help prevent or minimise jet lag.

Symptoms of jet lag can vary. You may experience only one symptom or you may have more than one.

A disruption to your circadian rhythms

Jet lag can occur anytime you cross two or more time zones. Jet lag occurs because crossing multiple time zones puts your circadian rhythms, which regulate your sleep-wake cycle, out of sync with the time in your new locale.

For example, if you leave Dhaka on a flight at 4 pm on Tuesday, and arrive in London at 7 am Wednesday, your internal clock still thinks its 1 am in Dhaka. That means you are ready for bed just as British are waking up. And because it takes a few days for your body to adjust, your sleep-wake cycle, along with most other body functions, such as hunger and bowel habits, remains out of step with the rest of London.

The influence of sunlight

A key influence on your internal clock is sunlight. That is because light influences the regulation of melatonin, a hormone that helps synchronise cells throughout the body. Certain cells in the tissue at the back of your eye (retina) transmit the light signals to an area of your brain called the hypothalamus. At night, when the light signal is low, the hypothalamus tells the pineal gland, a small organ situated in the brain, to release melatonin. During daylight hours, the opposite occurs, and the pineal gland produces very little melatonin.

You may be able to ease your adjustment to your new time zone by exposing yourself to daylight in the new time zone so long as the timing of light is done properly.

Medications

Sleeping pills like Benzodiazepines (such as Diazepam) may help you sleep during your flight and for several nights afterward. Side effects are uncommon. Although these medications appear to help sleep duration and quality, they may not lessen daytime symptoms of jet lag. These medications are usually only recommended for people who have not been helped by other treatments.

Light therapy

Your body's internal clock is influenced by exposure to sunlight, among other factors. When you travel across time zones, your body must adjust to a new daylight schedule and reset, allowing you to fall asleep and be awake at the appropriate times. Light therapy can help ease that transition. It involves exposing your eyes to an artificial bright light or lamp that simulates sunlight for a specific and regular amount of time during the time when you are meant to be awake.

So try these methods after your long haul of flight and get rid of the jet lag.

The writer is an Assistant Professor of Medicine at Z H Sikder Women's Medical College & Hospital, Dhaka.