- acute sinusitis;
- an arterial tear;
- a blood clot;
- a brain aneurysm;
- carbon monoxide poisoning;
- a concussion;
- dehydration;
- an ear infection; and
- meningitis.
4. You have a constant headache that gets worse over time.
Harvard Medical School has stated that most headaches that are not serious last between 20 minutes and two hours. Therefore, if your headaches last 24 hours or longer and get worse over time, they could be the result of something more serious happening in your body.
On the other hand, it is possible for headaches that last 24 hours or more to be migraines. A migraine is different than a simple tension headache because it is much more severe and could result in light sensitivity, seeing wavy lines or temporary loss of vision.
Migraine sufferers may experience nausea, congestion and eye watering. Often sufferers mistake migraines for sinus or tension headaches, so it is often recommended that you seek medical attention if your headaches last more than 24 hours and/or worsen over time.