Research by the National Institutes of Health (NIH) indicates that women often experience new or different physical symptoms as long as a month or more before experiencing heart attacks.

Among the 515 women studied, 95% said they knew their symptoms were new or different a month or more before experiencing their heart attack, or Acute Myocardial Infarction (AMI). The symptoms most commonly reported were unusual fatigue (70.6%), sleep disturbance (47.8%), and shortness of breath (42.1%).

Many women never had chest pains

Surprisingly, fewer than 30% reported having chest pain or discomfort prior to their heart attacks, and 43% reported have no chest pain during any phase of the attack. Most doctors, however, continue to consider chest pain as the most important heart attack symptom in both women and men.

The 2003 NIH study, titled "Women's Early Warning Symptoms of AMI," is one of the first to investigate women's experience with heart attacks, and how this experience differs from men's. Recognition of symptoms that provide an early indication of heart attack, either imminently or in the near future, is critical to forestalling or preventing the disease.

In a NIH press release, Jean McSweeney, PhD, RN, Principal Investigator of the study at the University of Arkansas for Medical Sciences in Little Rock, said, "Symptoms such as indigestion, sleep disturbances, or weakness in the arms, which many of us experience on a daily basis, were recognized by many women in the study as warning signals for AMI. Because there was considerable variability in the frequency and severity of symptoms," she added, "we need to know at what point these symptoms help us predict a cardiac event."

Women's symptoms not as predictable

According to Patricia A.Grady, PhD, RN, Director of the NINR:

Increasingly, it is evident that women's symptoms are not as predictable as men's. This study offers hope that both women and clinicians will realize the wide range of symptoms that can indicate heart attack. It is important not to miss the earliest possible opportunity to prevent or ease AMI, which is the number one cause of death in both women and men.

The women's major symptoms prior to their heart attack included:

Unusual fatigue - 70%

Sleep disturbance - 48%

Shortness of breath - 42%

Indigestion - 39%

Anxiety - 35%

Major symptoms during the heart attack include:

Shortness of breath - 58%

Weakness - 55%

Unusual fatigue - 43%

Cold sweat - 39%

Dizziness - 39%

Related NIH research into heart attacks in women includes possible ethnic and racial differences.