Stroke, Bell's palsy, and sudden deafness are conditions that each have a specific window of time to get evaluated or treated. Learn the signs and seek immediate help to reverse or reduce any disability.

Stroke

There are two kinds of stroke. An ischemic stroke is a blockage that prevents blood flow to the brain. A hemorrhagic stroke is caused by bleeding in the brain, says David Wang, DO, FAAN, chair of the American Academy of Neurology Stroke Section and clinical professor of neurology at the University of Illinois College of Medicine at Peoria.

Know the signs:

• Facial droop
• Arm or leg weakness
• Speech problems (an inability to speak or garbled speech)
• Sudden bad headache
• Double vision
• Difficulty walking
• Vision loss
• Sudden loss of sensation on one side of the body

Consider it an emergency: Recovery from a stroke is possible, but the window for treatment with a drug called tissue plasminogen activator (tPA) for ischemic stroke is about four and a half hours from the time symptoms begin, says Dr. Wang.

Take action: Call 911 immediately and let the operator know of a possible stroke. All paramedics are trained to identify a stroke and transport the victim to the closest stroke care hospital.

Bell's Palsy

Bell's palsy causes temporary paralysis or weakness on one side of the face, including the forehead, eye, and one side of the mouth. It's likely caused by inflammation of the nerve responsible for facial movements, possibly due to a virus that affects the nerve, says Steven L. Lewis, MD, FAAN, chief of neurology at the Lehigh Valley Health Network in Allentown, PA.

Know the signs:

• Drooling and difficulty keeping liquids in the mouth
• Facial drooping that's noticeable to others
• Dryness of the eye or mouth
• Inability to wrinkle muscles of the forehead, close the eye, smile, or move the mouth on the affected side
• Sensitivity to sound on the affected side
• Impaired taste
• Excessive tearing in one eye

Consider it an emergency: Because Bell's palsy resembles stroke, it's crucial to get to the emergency department as soon as possible so a doctor can determine the cause. If it's Bell's palsy, doctors will often prescribe steroids. Even without treatment, most patients' symptoms resolve within two weeks.

Take action: Call 911 immediately. If imaging and blood tests rule out a stroke, hospital personnel will likely treat with steroids and recommend follow-up with your doctor.

Sudden Deafness

Sudden deafness, or sudden sensorineural hearing loss, is an unexplained, rapid loss of hearing, says Robert W. Baloh, MD, FAAN, professor of neuro-otology at the David Geffen School of Medicine at UCLA. Common causes are infectious diseases (usually viral) of the ear or auditory nerve; trauma, such as a head injury; circulation problems; Meniere's disease; and autoimmune disorders.

Know the signs:

• Inability to hear people talking on one side
• A loud "pop" just before hearing goes
• Dizziness, ringing in the ears, or both

Consider it an emergency: It's critical to get treatment right away; if the sudden deafness has an underlying cause such as an infection, and the infection is treated immediately, the hearing loss may be reversible, says Dr. Baloh.

Take action: Patients should see their primary care physician or go to an emergency department or urgent care center as soon as possible, says Dr. Baloh. Doctors will examine the ear and check hearing as well as take a full medical history. Many people recover hearing in a week or two without treatment, and more recover hearing after treatment, which can include steroids to reduce inflammation due to viral infection, antibiotics for bacterial infection, and antiplatelet drugs for impaired circulation. "There's no absolute window for treating sudden deafness caused by autoimmune disease with steroids, but the sooner the better," says Dr. Baloh.