Not only does all work and no play make us dull—it can also make us sick, according to experts and research on the subject of stress.

How do you avoid this particular illness? Our doctors suggest reinventing how you think about vacations, treating them as necessary breaks that help us keep our lives in balance—not as a luxury.

"Working very hard and only getting relief when you go on vacation is a failing model," says Dr. Waguih William IsHak, vice chair of the Cedars-Sinai Department of Psychiatry. "What happens is that people live very stressful lives, disconnect from that stress when they go on vacation, but resume the cycle when they get back to work. That's not the way to do it."

Instead, Dr. IsHak recommends an ongoing balance between three main activities: work, love, and play.

Work may be your job, volunteer activities, or commitments as a student or a homemaker. It's anything that has a start and stop time with a defined task.

"Then you have love, which are intimate relationships, family relationships, friendships, and even simple moments of connection with other people. That's all in the realm of love," Dr. IsHak says.

The third activity is drug- and alcohol-free play where people get to do the things that they enjoy. These aren't necessarily goal-oriented activities.

"Think back about how kids play," Dr. IsHak explains. "There is not necessarily a purpose other than having fun. Maybe you enjoy taking a walk, playing cards, watching comedy. It doesn't matter what it is. The key is balancing those three main categories—work, love, and play—throughout the year."

Because time is our most significant asset, finding work-life balance depends on the decisions we make every day.

Read: Stressed? Try Mindfulness

"Having a nice vacation once or twice a year helps you disconnect from your regular environment," says Dr. IsHak. "You develop perspective on what you're doing, where you're going in life, and what makes you happy. You can think about changes you'd like to make."

But Dr. IsHak says these kinds of vacations serve as play that only partially balances the hard work during the rest of the year.

Balance also needs to happen each month as we make time to nurture our relationships and schedule play activities. A short monthly trip, time off from work, or an activity every month that gets us out of the normal routine is very valuable.

"We should balance the week between workdays and days off. Despite our long hours on the job, are we seeing our loved ones and making relationship connections? Are we using our days away from work to create time for activities based on play instead of constantly working?"

We should even find daily balance by including the relationship realm or play during work hours.

Spending the entire day on our tasks is exactly how most people burn out. "They wait until the end of the day or week, or even the end of the month or year for relief," Dr. IsHak says. "But rebalancing has to happen at every level—all throughout the calendar."

Read: Reiki Brings Relaxation to Cedars-Sinai Patients

So, what happens to us if we're out of balance?

Sleep disruption
When stress hits, our ability to sleep takes a hit. Falling out of balance can lead to difficulty staying asleep or waking up up too early—fretting about work.

Changes in appetite
Diet is also responsive to stress. When we fall out of balance and start feeling stressed, our appetite can swing one way or the other and we may seek out sugary/salty comfort foods or experience the opposite and lose all food cravings. If eating becomes one of the few sources of comfort during a stressful day at work, that can lead to long-term health consequences, including obesity.

Read: 8 Expert Tips to Avoid Getting Sick When You Travel

Depression
Chronic stress and sleep deprivation can lead to depression and a spectrum of anxiety disorders and health issues, including tension headaches, migraines, asthma and breathing problems, elevated blood sugar levels, immune system issues, and gastrointestinal problems.

Increased risk of heart disease and heart attack
"There is also evidence that people who skip vacations consecutively for many years have a 30% or more higher risk of suffering a heart attack," says Dr. P. K. Shah, director of the Atherosclerosis Prevention and Management Center at the Smidt Heart Institute. "Even missing one year's vacation seems to be associated with an increased risk of heart attack."

"We see the stress levels go down in people who take time off from work," explains Dr. Shah. "Stress is clearly linked to increased risk of heart disease and heart attack." But the studies don't prove causality. "It could be that people who are intrinsically healthier take more vacation; not the other way around.

"Regardless, I think the overall impression is that vacation is good for mind, body, and soul."