Migraines Vs. Sinus Headaches

Overview
Sinus headaches and migraines are often confused, because many of the symptoms are the same. Both consist of throbbing or aching pain in one or both sides of the head. Both sinus headaches and migraines can become worse if you bend forward. Both sinus headaches and migraines can have nasal congestion as an additional symptom, along with the headache. However, there are some primary differences between migraines and sinus headaches, in both symptoms and causes. For example, migraine sufferers may feel nausea during a migraine, while those suffering from a sinus headache will not experience this symptom. Furthermore, migraines are made worse by light and noise, while sinus headaches are not affected.
Migraines
A migraine is the name for a severe, recurrent headache. The National Migraine Association estimates that approximately 36 million Americans have migraines. Migraines themselves are a disease, caused by expansion of the cranial blood vessels. The headaches are only a symptom of the disease, and differ from traditional non-migraine headaches, which are caused by a narrowing of the cranial blood vessels. Migraine headaches may be accompanied by sensitivity to sound, light, smell and nausea. They can be difficult to diagnose, because symptoms vary and resemble those of other illnesses, including sinus headaches.
Causes of Migraines
The National Migraine Association states that migraines are a genetic disease; children whose parent(s) experience migraines are 50 percent more likely to experience migraines themselves.

Migraine headaches are caused by both manageable and unmanageable triggers. Manageable triggers, or triggers you can control, include alcohol, aspartame and bright light. Manageable triggers, or triggers you can't control, include menstrual cycles and weather patterns.

Sinus Headaches
Sinus headaches, like migraines, can cause the front of your head to experience a dull, deep or throbbing pain. The pain or pressure may be specific to one area of the head, and may worsen in the morning or when you stand or bend forward. Changes in temperature may make the pain worse, and the pain is typically worse in the morning. The headache may be accompanied by postnasal drip, a runny noise, nasal congestion, a fever and a general sense of being tired and feeling ill.
Causes of Sinus Headaches
Sinus headaches are caused by congestion and inflammation. Respiratory infections or allergies can cause the sinuses to become inflamed and prevent the natural drain of mucus. The mucus gets blocked and provides a home for the rapid growth of bacteria, fungi and viruses. This can all combine to cause pressure, which leads to a sinus headache. As a result, sinus headaches often follow colds or allergy attacks.
Diagnosis
Typically, your doctor will do several things to distinguish a sinus headache from a migraine. The doctor will inquire as to whether you have experienced a recent cold or allergy attack. The doctor may ask if you have experienced the other symptoms associated with a sinus headache that are not associated with migraines, such as postnasal drip.

The doctor will follow up the questions with a physical exam. He will look in your nose to see if it is congested, or shine a light on your sinuses (transillumination). X-rays, CT scans or MRIs may be able to diagnose blocked sinus passages.

Resources
reference
Migraines.org
reference
University of Maryland Medical Center