Health experts caution that heart attacks often don’t strike without warning—many subtle symptoms may appear up to a month in advance, offering a vital window for intervention. 

1. Unusual fatigue—an overwhelming tiredness not tied to exertion, often lingering even after rest.

2. Shortness of breath—difficulty breathing during light activity or at rest, signaling weakened heart pumping.

3. Sleep disturbances, including insomnia, night sweats, or waking gasping, often accompany fatigue and chest discomfort.

4. Indigestion, nausea, or abdominal pain, which can mimic gastric issues but may reflect cardiac distress.

5. Chest discomfort, a mild pressure or heaviness that may come and go, progressing over weeks.

Although often overlooked or attributed to non-cardiac causes, these signals—especially when clustered—should prompt medical evaluation. Recognizing them early is critical; timely action can help avert a full-blown heart attack.

In a related report, experts highlight additional subtle “red flags” including lightheadedness, leg swelling, palpitations, and digestive symptoms—particularly in women—underscoring the importance of attentive self-monitoring and routine checkups.