It may occur during physical activity, but symptoms can also happen at rest.

There are many non-cardiac causes of chest discomfort, including acid reflux, muscle strain, inflammation, and anxiety.

But because a heart attack can be life-threatening, new or unexplained chest pressure should be taken seriously.

If chest discomfort is severe, persistent, or accompanied by shortness of breath, sweating, nausea, fainting, or pain spreading to the arm or jaw, seek emergency medical care.

5. Waking Up With a Sudden Feeling of Weakness or Extreme Fatigue

Some people with cardiovascular disease experience significant fatigue or weakness.

Heart failure, for example, can reduce the body's ability to deliver oxygen-rich blood efficiently, making ordinary activities feel much more exhausting.

But fatigue is one of the least specific symptoms in medicine.

Poor sleep, anemia, infections, thyroid problems, medications, depression, sleep apnea, and many other conditions can cause similar feelings.

What matters is a new or unexplained change.

If you suddenly become much more fatigued than usual—particularly if the change occurs alongside breathlessness, swelling, chest discomfort, dizziness, or reduced exercise tolerance—talk with a healthcare professional.

Why Symptoms Can Become More Noticeable at Night

There is a reason some symptoms seem worse after bedtime.

When you're lying down, fluid that has accumulated in the legs during the day can move back toward the chest.

In someone with impaired heart function, the heart may struggle to handle this additional fluid effectively.

This can contribute to increased pressure in the lungs and make breathing more difficult.

That is one reason orthopnea and paroxysmal nocturnal dyspnea are recognized symptoms of heart failure.

But nighttime symptoms aren't exclusively cardiac.

Your sleeping position, airway anatomy, medications, alcohol consumption, meal timing, and sleep disorders can all influence what you experience overnight.