Stroke can affect people in different ways. It depends on the type of stroke, the area of the brain affected and the extent of the brain injury. Brain injury from a stroke can affect the senses (such as eyesight, touch, awareness of body positioning), motor activity (movement of arms or legs), speech and the ability to understand speech. It can also affect behavioral and thought patterns, memory and emotions. Paralysis or weakness (the inability to move the arms or legs properly, or at all) on one side of the body is common.

After a stroke, most of these problems can improve over time. In some patients they will go away completely.

How can a stroke affect emotions?

Some areas of the brain produce emotions, just as other parts produce movement or allow us to see, hear, smell or taste. If these areas are injured by a stroke, a survivor may cry easily or have sudden mood swings, often for no apparent reason. This is called emotional lability. Laughing uncontrollably also may occur but isn't as common as crying. Depression is common as stroke survivors recover and as they come to terms with any stroke-related impairment that doesn't fully go away.

How can a stroke cause loss of awareness?

Stroke often causes people to lose mobility and/or feeling in an arm and/or leg. If this affects the left side of the body (caused by a stroke on the right side of the brain), stroke survivors may also forget or ignore their weaker side. This problem is called neglect or inattention. As a result, they may ignore items on their affected side and not think that their left arm or leg belongs to them. They also may dress only one side of their bodies and think they're fully dressed. Bumping into furniture or door jambs is also common. Sometimes, they may ignore the food on the left side of their plate.

How can a stroke affect perception?

A stroke can also affect seeing, touching, moving and thinking, so a person's perception of everyday objects may be changed. Stroke survivors may not be able to recognize and understand familiar objects the way they did before. When vision is affected, objects may look closer or farther away than they really are. This causes survivors to have spills at the table or collisions or falls when they walk.

How can a stroke affect hearing and speech?

Stroke usually doesn't cause hearing loss, but people may have problems understanding speech. They also may have trouble saying what they're thinking. This is called aphasia. Aphasia affects the ability to talk, listen, read and write. It's most common with a stroke on the left side of the brain (because the speech and language center of the brain is located on the left side of the brain), which may also weaken the body's right side. Another possible symptom of a left-brain stroke is weakness on the right side of the body.

A related problem is that a stroke can affect muscles used in talking (those in the tongue, palate and lips). Speech can be slowed, slurred or distorted, so stroke survivors can be hard to understand. This is called dysarthria. It may require the help of a speech therapist.

How can a stroke affect chewing and swallowing food?

The problem with chewing and swallowing food is called dysphagia. It can occur when muscles on one side of the mouth are weak. One or both sides of the mouth can also lack feeling, increasing the risk of choking.

How can a stroke affect the ability to think clearly?

Parts of the brain allow us to form long-term and short-term memories. (Short-term memories help us remember why we got up and walked into the next room, for example.) With injury to these areas, it may be hard to plan and carry out even simple activities. Stroke survivors may not know how to start a task, confuse the sequence of logical steps in tasks, or forget how to do tasks they've done many times before.

It's important for stroke survivors to receive appropriate rehabilitation to help alleviate deficits caused by a stroke.

For stroke information, call the American Stroke Association at 1-888-4-STROKE.

Related AHA and ASA publications:

• Understanding Stroke (also in Spanish)
• Caring for Someone With Aphasia
• How Stroke Affects Behavior
• Living With Disability After Stroke  
• Sex After Stroke
• American Heart Association Family Guide to Stroke: Treatment, Recovery, and Prevention (available where books are sold)
• Sheets from Let's Talk About Stroke kit