You know that feeling you get when you’re newly in love? Your palms sweat, your knees get weak, and your heart feels like it might leap out of your chest. This happens because your brain sends a signal to your adrenal glands, which release hormones that trigger physical responses to love.

But what’s going on with heart palpitations that occur when your love life isn’t so exhilarating? We checked in with Dr. Jennifer Erskine, medical director of Shore’s Hospitalist program, to find out what could be happening, and when to worry.

“Palpitations can be described as a fluttering, pounding or fast heartbeat. Most palpitations are just a harmless interruption in your heart rhythm. If they’re only happening once in awhile, it’s probably nothing to worry about. But if you feel them frequently, you’ll want to see a doctor to get to the bottom of it,” Erskine says. 

“However, if you have heart palpitations accompanied by dizziness, fainting, chest pain or shortness of breath, you could be having a serious medical condition and need to seek emergency care.”

Here are some of the most common reasons behind your fluttering heart:

1. Stress and anxiety: Our psychological state is one of the most common causes of heart palpitations. If you’re nervous or stressed out, your brain releases hormones similar to those released when you’re in love, which can make your heart pound. If it occurs once in a while and when you’re noticeably stressed, it’s probably harmless. If you can’t control your stress, you could have an anxiety or panic disorder and should see your doctor. Stress over time can have a serious effect on your heart.
2. Hyperthyroidism: Your thyroid releases hormones that affect your cells, and therefore all areas of your body. An overactive thyroid is releasing too many hormones, which can speed up all of your systems, including your heart rate.
3. Drugs: Certain cold medications, especially those that contain pseudoephedrine, and some prescription medications can cause heart palpitations. Caffeine, diet pills and illicit drugs like cocaine can also cause a racing heart. Obviously, eliminating those sources will likely prevent palpitations from occurring.
4. Pregnancy: During pregnancy, you may have palpitations as a result of the increased blood volume in your body. Some women become anemic during pregnancy, which can also cause palpitations.
5. Heart valve problems: Mitral valve prolapse is one condition that can cause palpitations. When the two flaps of your mitral valve don’t close evenly, a small amount of blood may leak backward through the valve. This can cause a heart murmur and other symptoms like palpitations. It’s usually not serious, but should be evaluated.
6. Hypoglycemia: Low blood sugar can also cause palpitations because it releases stress hormones to help your body function in absence of the glucose it needs. Those stress hormones can cause your heart to race.

Remember, if you don’t have an obvious reason for heart palpitations like a new love interest sending your heart aflutter, it’s important to bring it up with your doctor. Although most heart palpitation causes are benign, they could signify an underlying problem like those mentioned above. To determine the cause and rule out any serious heart conditions, your physician may schedule you for an EKG, which tests the electrical connectivity of your heart. Lab testing may be scheduled to rule out thyroid disorders or anemia, or your physician may even send you home with a Holter monitor to wear at home to record your heart palpitations.