You can’t focus, you’re anxious, sleepy and constipated. What’s wrong? If you’ve been traveling across time zones, it’s quite probable you have jet lag. Jet lag is classified by experts as a circadian rhythm sleep disorder and it’s caused when your internal clock is off kilter due to major changes in your sleep schedule.

There are few things worse than finally arriving at your much-anticipated destination and being unable to focus due to lack of sleep. So, how can you quickly get over jet lag and go on to enjoy your vacation? The following are some tips:

1. Start with prevention: Get plenty of rest, fluids and exercise before you embark. You may also want to adjust your at-home sleep schedule to match the time zone of your destination. For example, if you’re traveling east to west, go to sleep later and awaken later for several days before leaving.

2. Take care while flying:

- Avoid caffeine and alcohol during your flight, as these intensify jet lag and can cause further dehydration
- Take along an eye mask and earplugs to help you sleep during your flight
- Get up and stretch often to keep your blood circulating
- Schedule layovers for longer flights if possible: Breaking up a long flight into shorter segments can often provide enough of a break to allow your body to adjust to the time change more quickly

3. Give yourself time after you arrive: Get some sunlight if possible and schedule time for naps for the first day or two to help you catch up on your sleep.

If jet lag is a regular challenge for you, consider additional approaches, including:

- Light therapy, such as this one studied by the American Academy of Sleep Medicine, may stimulate your body’s internal clock to adjust to new time zones more quickly
- Melatonin may reduce the duration of jet lag in some people
- The creators of the Anti-Jet Lag Diet claim that by eating the right foods, you can avoid jet

Need to find a great restaurant nearby? There’s an app for that. Need to identify a song playing on the radio? There’s an app for that. Need to get some decent shut-eye? Not surprisingly, there are several iPhone apps for that.

iPhone apps, or applications, are available in the Apple iTunes Store and come in two varieties: free or paid. Often the free editions (sometimes referred to as “lite”) contain basic features that allow you to get a feel for the application and are upgradeable to a paid version that contains all the bells and whistles. Here’s a sampling of both types of apps that claim to help you fall and stay asleep:

Pure Sleep/Ambiscience by Tesla Audio Sciences (basic is free; upgrade is 99 cents) uses ambient music and “brainwave entrainment” to create a response in the brain that induces sleep. There are several similar apps available, including SleepStream (99 cents) and Brain Wave – 20 Binural ($1.99).

White Noise by TM Soft ($1.99) blocks out disturbing noises by enabling you to choose from 40 soothing sounds such as a steady fan, running water, crickets, light rain and more. The app also includes a sleep timer and alarm buzzer. Sleepmaker Rain by Software X Ltd offers a free version that includes two rain sound tracks as well as an upgrade version, Sleepmaker Rain Pro ($2.99), that lets you choose from several options within the gentle, medium and heavy rain sound categories.

Sleep Tracker is a free app by Tylenol PM that helps you record your sleeping hours and moods so you can identify trends in your sleep and moods over time. The app also lets you create a sleep journal, and gives you access to dozens of tips for a better night’s sleep. iSleepTracker by Health Ventures (99 cents) offers similar features and enables you to e-mail your sleep history to your health care provider.

ABC’s of Better Sleep – Insomnia Cure with Max Kirsten ($7.99) is a program developed by Max Kirsten, a clinical hypnotherapist, based on his work with patients with sleep difficulties. The hypnosis program offers techniques and hypnosis sessions that claim to help you create a habit of falling and staying asleep. Other hypnosis-based sleep apps include: Custom Hypnosis Lite (free) and Custom Hypnosis (99 cents).

New apps seem to appear daily, so if none of these work for you, keep checking the iTunes Store and you’re bound to find an app that will put you to sleep.