In recent decades, scientists have realized that heart attack symptoms can be quite different for women than for men.

The journal Circulation published the findings of a multicenter study of 515 women who’d experienced a heart attack.

The most frequently reported symptoms didn’t include chest pain. Instead, women reported unusual fatigue, sleep disturbances, and anxiety.

Nearly 80 percent reported experiencing at least one symptom for more than a month before their heart attack.

In a survey published in the journal Circulation, only 65 percent of women said they’d call 911 if they thought they might be having a heart attack.

Symptoms of a heart attack in women include:

Even if you’re not sure, get emergency care right away. Base your decision on what feels normal and abnormal for you.

If you haven’t experienced symptoms like this before, don’t hesitate to get help. If you don’t agree with your doctor’s conclusion, get a second opinion.

Unusual fatigue lasting for several days or sudden severe fatigue

Profound and unexplained fatigue or a sudden decrease in energy levels can sometimes be a warning sign of a heart attack in women.

Sleep disturbances

Sleep disturbances, such as insomnia, unusual restlessness, or waking up frequently during the night, have been reported as warning signs in some women prior to a heart attack.

Anxiety

Some women may experience a sense of impending doom, anxiety, or a feeling that something is terribly wrong during a heart attack.

Lightheadedness

Feeling dizzy or faint is another symptom that may occur during a heart attack.

Shortness of breath

Feeling breathless or having difficulty catching your breath can be a symptom of a heart attack. This may occur with or without chest discomfort.

Indigestion or gas-like pain

Some women may feel nauseated or may vomit during a heart attack, which can be mistaken for other gastrointestinal issues.

Cold Sweats

Cold and clammy skin, along with sweating, can accompany a heart attack, especially in women.

Jaw pain or pain that spreads up to your jaw

Women may experience pain or discomfort in areas other than the chest, such as the neck, jaw, shoulder, back, or stomach. This pain may radiate from the chest and is often a more subtle symptom.

Pressure or pain in the center of your chest, which may spread to your arm

While chest pain is a common symptom in both men and women, women may experience different types of chest discomfort. It can be described as a squeezing, fullness, pressure, or burning sensation in the chest that may come and go.