Sometimes, we just have one of those bad-mood days. The kind of day when, for no apparent reason, you're just not happy. Having a bad mood every once in a while is completely normal, but if you find yourself having them on a consistent basis, it may be negatively affecting your health. Besides the not-so-good feeling of a bad mood, it can potentially bring on illness, increase blood pressure and blood sugar, and interrupt sleep. As it turns out, bummed-out feelings may change the levels of stress-inspired chemicals in your brain, such as cortisol and adrenaline, which can have major effects on the nervous and immune systems, according to the journal Molecular Psychiatry.

At the same time, when a bad mood strikes, another brain chemical called opioids can increase as a way to offset distress. This brain chemical can lower your immune system, making you potentially more likely to get sick, according to PsychCentral.

The more days you spend in a funk, the more likely it is to elevate stress hormones such as cortisol, which can affect your blood pressure, blood sugar, and sleep quality.

Besides the effects on your physical health, a bad mood can affect your emotional health, too. It may leave you feeling isolated, disconnected, and can even cause others to feel depressive, too—a sort of bad mood domino effect.

A new study published in Psychophysiology shows that when people are in a bad mood they are less empathetic to people in pain. That means they may be less tuned in to others than people who are in a good mood.

Even though we can’t avoid bad moods, we can be aware of them when they hit, trying to shake it off when possible. Here are a few ways to help ramp up your endorphins and hopefully increase your connection with others in the process.

Surround yourself with smiles

You’ll have a 25 percent higher chance of feeling better if a nearby friend is happy, according to a Harvard study. On the contrary, if a friend of colleague is in a sour mood, it can be passed along, as we tend to copy one another’s nonverbal cues, according to a University of Notre Dame study.

Exercise

A walking or running routine can change your mood. When exercising, your brain releases endorphins that work to reduce your perception of pain, according to WebMD.

Get outside

Going for a walk in nature may help to decrease anxiety and negative thoughts, and increase positiveemotions and even your memory, according to the journal Landscape and Urban Planning.