A good night's sleep is necessary for health. Less than seven hours per night historically leads to chronic diseases prevalent in this country, such as heart disease, obesity, and type 2 diabetes.

It is also necessary for proper functioning at work, school, and home. Insufficient sleep can cause us to lose our tempers with loved ones and co-workers. It can reduce our resilience and increase our response to stress.

It can even increase our risk of vehicle accidents, as drowsy driving correlates to a heightened risk of crashes. People who are tired or sleep can't respond as quickly to traffic conditions, and their judgment may be impaired.

Unfortunately, about one-third of Americans say that they don't get enough sleep. It's a public health crisis, as well as a personal one. It's common knowledge that seven hours or more is necessary for high functioning. If you're getting less, you have a problem.

Fortunately, though, there are some actions you can take to increase your amount of sleep. Here are six ideas to try when you can’t get enough shut-eye.

1. Try to identify why you don't get enough sleep

The first thing to do is to determine why you don't get enough. Set aside some time to jot down the top 10 thoughts that come to mind in answer to the question "why don't I get enough sleep?"

You do this because reasons vary widely. You may have neighbors who choose to play loud music at 2:00 am. Keep in mind that some factors can cause you to get insufficient sleep.

Then, choose from the following list, according to what your identified factors are.

2. Coffee drinker? Knock it off in the afternoon

Coffee has caffeine. Yes, even decaffeinated coffee has it. The best way to make sure coffee isn't affecting your sleep is to cut it out entirely in the afternoon. The less coffee, the better if you're having sleep problems. If you drink three cups a day, try to cut down to one.

Remember that tea also has caffeine, although it has less than coffee. If you're a tea drinker, it's also advisable to eliminate post-noon consumption and cut down your daily intake.

3. Eliminate loud noises at night

If those music-loving neighbors are the reason you can't fall asleep or stay asleep, you have to make that stop. Human beings are hard-wired to wake up if there's noise. If it's friends or family listening to television, traffic, or any other sound, you have to find a way to create a quiet sleep environment.

We realize there are several ways of doing this. First, try to talk to the people causing the noise. If it's loud neighbors, recognize that you can call the police about a disturbance.

But there are times when that doesn't work, or a specific set of people isn't the problem. In that case, you have to make sure you can't hear loud noises. Try earplugs designed explicitly for people who have trouble sleeping.

If you open your windows, shut them and use fans or air-conditioning instead. Some people find white noise machines helpful or fall asleep faster listening to soothing sounds like ocean waves.

Experiment until you find what works for you.

4. Make your bedroom dark

Darkening your bedroom is a simple solution, but it's amazing how many people don't realize it's their problem. Your bedroom could be too light to let you sleep. Just like we're hard-wired to wake up if we hear a noise, we're hard-wired to be wakeful if it's light.

Identify the source of the problem. Does your partner stay up with a reading light? Negotiate and work out a solution. Ask if they would mind reading in the living room instead.

Are there bright lights outside your bedroom window? Blackout curtains should do the trick. Venetian blinds or shutters can let light in even if they're closed. Heavy curtains eliminate or reduce that issue.

Is light under the door an issue for you? It is for some people. Here, too, you may have to adjust your body if you can't eliminate light in your environment. Eyeshades work. Try a comfortable, dark pair. It will make your vision stay black all night, and that's what you need.

5. De-stress before bedtime

For many people, trying to fall asleep opens the door to reliving all their daily stresses—or potential future stresses. You replay your conversations with the snide co-worker, the critical boss, the difficult in-law, this time with the perfect comeback.

Everybody has stressors. You have to create a bedtime ritual that is comforting and soothing rather than a bridge to thinking about stress. It's very reasonable and natural to spend 15 to 30 minutes to fall asleep. You need to relax and detach from the day gradually.

You might want to listen to your favorite quiet music. Some people like a meditative video, like a cat purring or a fireplace, crackling—many of which are on YouTube. A few pages of a good book also works wonders.

6. Get into a sleep routine

Some people can't sleep because they aren't in a habit. One night, they watch a movie until 1:00 am. The next night, they turn in at 10:00 pm. On weekends, they go out until 3:00 am. Sunday night, they turn in early, hoping for a good, restful night.

Surprise, surprise! We are creatures of habit when it comes to sleep. Once you've spent every few days up until 1:00 am, your body doesn't regard 10:00 pm as "bedtime" anymore. So, you may be wakeful even if you manage to fall asleep earlier because your body clock isn't set up for it.

The good news is that body clocks can undergo a reset. Figure out your ideal bedtime, and then stick to it. If a good movie is on television, record it. It may take a while, but eventually, your body will get the message. It's easier to fall asleep if you go to bed at roughly the same time every night.