3. You Have Trouble Understanding Others.
A person who is suddenly having a hard time speaking, or is slurring his or her speech, may have recently suffered a stroke. Difficulty speaking, as well as difficulty understanding what others are saying, are serious signs [4], and medical attention should be sought immediately.
4. You Feel Dizzy/Light-Headed.
According to the National Institutes of Health, a sign of atrial fibrillation is an onset of dizziness, or a fainting spell. This occurs because afib causes the ventricles in the heart’s lower chambers to contract more quickly than normal, and that prevents them from properly filling with blood.
Dizziness can occur for a myriad of other reasons, but if you experience dizziness or fainting combined with other listed symptoms, consult your doctor.
5. You Have a Terrible Headache.
Most headaches are not cause for concern, and can be attributed to a variety of things, including caffeine withdrawal, stress and anxiety, or sinus congestion.
However, a headache that comes on instantly, and is excruciating, could be a sign of hemorrhaging in the brain [5], and you should seek medical help immediately.