Dizziness (Dizzy)

Introduction to dizziness (feeling dizzy)

Dizziness is one of the most common symptoms that will prompt a person to seek medical care. The term dizziness (or dizzy) means different things to different people, so it is difficult to define. Does "feeling dizzy" mean lightheadedness or the feeling of weakness and almost passing out? Or does it refer to the sensation of vertigo, in which a person feels as if they have just gotten off a merry-go-round?

Dizziness (lightheadedness) is often caused by a decrease in blood supply to the brain, while vertigo may be caused by disturbances of the inner ear and the balance centers of the brain. It is important that the health care practitioner understand what you mean when you complain of dizziness. You may be asked additional questions so that the proper direction can be taken for a diagnosis and treatment.

What are some common causes of dizziness?

While classifying dizziness into lightheadedness and vertigo categories may help understand how the body works, sometimes it is worthwhile to review common reasons why people might complain of dizziness.

Low blood pressure

Dizziness, lightheadedness, and the feeling of passing out is a common complaint in people who have low blood pressure. When the blood pressure is too low, not enough oxygen-rich blood is being delivered to the brain, and its function can be affected. If the brain's blood supply is decreased too much, the person may pass out (syncope).

In addition to feeling dizzy, associated symptoms may include:

• sweating,
  
• nausea and vomiting,
  
• shortness of breath, and
  
• chest pain.

Low blood pressure may be the result of an underlying illness or disease, or it may be a normal physiologic condition. Some common reasons for low blood pressure include the following:

• Anemia (decreased red blood cell count)
  
• Bleeding
  
• Dehydration (loss of water in the body) often occurs with infections that cause vomiting and diarrhea. Fever also can cause a significant amount of water loss due to increased metabolic rate and excessive sweating as the body tries to cool itself.
  
• Heat-related illnesses associated with dehydration such as heat cramps, heat exhaustion, or heat stroke (a medical emergency).
  
• Side effects of certain medications used to control blood pressure and heart rate. Examples include:
  
  • beta blockers (propranolol [Inderal, Inderal LA], atenolol [Tenormin], metoprolol, [Lopressor, Toprol XL]), which block adrenalin receptors in the heart and may limit the ability of the heart rate to increase in response to changes of position, decreased red blood cell count, or dehydration.
    
  • Nitroglycerin and isosorbide mononitrate (Imdur), a long acting nitroglycerin, are medications that are prescribed to dilate blood vessels in the heart to treat angina. However, these medications may also cause other blood vessels in the body to dilate and be unable to respond to the body's needs.
    
  • Diuretics that can cause dehydration
    
  • ACE inhibitors that slow the heart rate, and
    
  • medications for erectile dysfunction that can dilate blood vessels.
    
• Alcohol use
  
• Pregnancy

Postural or orthostatic hypotension

In individuals who are dehydrated or anemic, blood pressure readings may be normal when they are lying flat, however, the lack of fluid is unmasked when they stand up quickly. The lack of blood to the brain causes dizziness and lightheadedness. This feeling may pass in a few seconds as the body adapts. However, if dehydration or medications (for example, beta blockers) prevent the body from reacting by constricting blood vessels and increasing the heart rate, the dizziness may persist to the point at which the patient passes out (faints, syncope).

Some diseases are associated with an inability to compensate for changes in body position (autonomic dysfunction). Normally when a person stands, blood vessels contract to increase blood pressure slightly,  and the heart rate increases to push blood up to the brain (pushing against gravity). In autonomic dysfunction, a person may become dizzy when they move from a lying position to sitting or standing up.  Examples of these diseases include diabetes, Addison's disease, or Parkinson's disease).

Orthostatic hypotension is a common symptom with Shy-Drager syndrome. Shy-Drager syndrome is a rare disease in which the autonomic nervous system degenerates and cannot provide the routine control mechanisms for the body including heart rate, blood pressure, and bowel and bladder function.

High blood pressure

High blood pressure, or hypertension, is known as the "silent killer" since it often has no symptoms, even if blood pressure readings are markedly elevated. On occasion, a person may complain of headache, nausea, or dizziness, although the complaints don't necessarily correlate with the degree of blood pressure elevation.

However, if the blood pressure is elevated and the person has symptoms, there is a need to bring the blood pressure under control relatively quickly. The more severe the symptoms, the quicker blood pressure control needs to be achieved. For example, if a person is having chest pain or stroke symptoms associated with high blood pressure, the blood pressure needs to be controlled immediately.

Diabetes

Dizziness is a common complaint in persons with diabetes, and may be caused by low blood sugar (hypoglycemia), high blood sugar (hyperglycemia), or autonomic dysfunction (see previously).

• Hypoglycemia or low blood sugar (hypo=low +glyc=sugar =emia=blood) occurs because of an inadequate amount of glucose in the blood. A person with diabetes can develop hypoglycemia from an inadequate amount of food intake, or from taking too much medication (insulin or oral tablets), which results in low blood sugar levels. In this situation the person experiences dizziness or lightheadedness because the brain lacks glucose to function properly. Persons with diabetes and their families need to recognize the symptoms of hypoglycemia, including dizziness, sweating, confusion, and coma as treatment needs to be given immediately. Oral sugar-containing foods or a glucagon injection may be life-saving for the patient.
  
• Hyperglycemia (hyper=high +glyc=sugar +emia=blood) also causes dizziness. High blood sugar levels occur because there is not enough insulin available to allow cells to use glucose for energy metabolism. (Interestingly, brain cells do not need insulin to use glucose.) High blood sugars cause a variety of metabolic responses in the body leading to dehydration, anaerobic metabolism, and changes in the acid-based balance. This may result in a life-threatening condition referred to as diabetic ketoacidosis. 

Endocrine diseases

• Diabetes (discussed previously) if not well controlled is one of the main endocrine diseases that may cause dizziness.
  
• Thyroid disease: Abnormalities of the thyroid may also cause dizziness as one of its symptoms.
  
  • Hyperthyroidism (too much thyroid hormone) may cause palpitations, shortness of breath, lightheadedness, and dizziness.
    
  • Hypothyroidism (too little thyroid hormone) may cause low blood pressure and a decreased heart rate leading to dizziness, weakness, lethargy, and chills.
  
  
• Addison's disease: Addison's disease occurs when the adrenal glands do not produce enough cortisol to meet the needs of the body. Cortisol is a naturally occurring steroid produced by the body and is part of the stress response (often termed the "fight or flight" response). If cortisol levels are low, a patient may experience weakness, fatigue, dizziness, lightheadedness, low blood sugar, and low blood pressure.

Hyperventilation

While the body may use hyperventilation or rapid breathing to help with acid-base balance, it may also occur as a response to an emotionally stressful situation. In hyperventilation syndrome, the rapid breathing blows off some of the body's carbon dioxide, leading to a tingling sensation in the hands and feet, and around the mouth. Dizziness and lightheadedness are associated symptoms. The symptoms may increase the perceived emotional stress and cause even more hyperventilation. In severe hyperventilation, carbon monoxide levels drop enough to cause carpopedal spasm, in which the hands and feet become claw-like and difficult to move. Symptoms of hyperventilation resolve relatively quickly once the breathing rate returns to normal.

Heart conditions

The heart is an electrical pump and for it to work, the electrical conduction system must be operating properly to stimulate the heart muscle to squeeze in a coordinated fashion and pump blood to the body. The heart muscle itself must be strong enough to pump blood, and the valves in the heart must work properly to allow blood to flow in the direction intended during contraction.

• Conduction disturbances: Electrical conduction disturbances may make the heart beat too quickly (tachycardia) or too slowly (bradycardia), and either of these situations may result in an inadequate blood supply to the brain, causing dizziness or lightheadedness.
  
• Cardiomyopathy: Dizziness is also a symptom of cardiomyopathy (cardio=heart +myo=muscle + pathy= disease), a disease of the heart muscle, resulting in muscle that doesn't beat properly. Most commonly the weakness is due to atherosclerotic heart disease or ischemic cardiomyopathy (ischemic=decreased blood supply), in which the heart muscle itself doesn't get enough blood supply to work properly. Other cardiomyopathies may be due to diabetes, alcohol use, and viral infections.

Vasovagal syncope

Vasovagal syncope is a common cause of dizziness, lightheadedness, and fainting. The vagus nerve is overstimulated and causes the body's blood vessels to dilate and the heart to slow down. This anti-adrenaline effect decreases the ability of the heart to pump blood upward to the brain. Without blood flow, the brain turns off. In Victorian England, when this happened because young ladies' sensibilities were easily offended, this was called a swoon.

Some people faint at the sight of blood. Some parents faint when their child gets immunized. Many types of emotional and physical stressors can overstimulate stimulate the vagus nerve, thus causing dizziness, lightheadedness, and at times fainting (passing out).

Fainting is not normal. If a person is unconscious, the emergency medical system should be activated (call 911 if available), and medical care should be sought.

Dizziness and vertigo

Vertigo is often described as feeling dizzy, or a sensation of spinning. A person may specifically mention that the room seems to be spinning around them. Sometimes the complaint is loss of balance or loss of equilibrium. This often occurs because of irritation in the inner ear (the part of the ear that involves balance, not hearing).

The inner ear has two parts that help the body determine its position in space relative to gravity; 1) the semicircular canals and 2) the vestibule.

There are three semicircular canals that are aligned at right angles to each other. These canals are filled with fluid and are lined with a nerve-filled, crystal-encrusted membrane that transmits information to the cerebellum (the part of the brain that controls balance and coordination). The cerebellum collects information from the eyes (visual stimuli) and the nerve endings in muscles associated with proprioception (the perception of movement), to assist the brain in assessing where the body is in relationship to gravity and its surroundings.

Normally, when the head moves, fluid in the semicircular canals shift, and that information is relayed to the brain. When the head stops moving, the fluid stops as well, and that information is relayed to the brain.

In some cases there may be a short delay in the transmission of this information to the brain. For example, when a person rides on a merry-go-round or spins quickly around in circles, the fluid in the canals develop momentum and even though the body stops spinning, the fluid in the semicircular canals may continue to move. This causes vertigo, or a sensation of spinning, and may cause the person to fall or stumble. It also may be associated with vomiting. While these are symptoms attempt to provoke in play, they can be debilitating for an adult.

• Inflammation: In patients with vertigo, inflammation of the fluid or irritation of the crystals on the membrane that lines the walls of the semicircular canals may cause the spinning sensation even without much head movement. Often, only one canal is involved and the patient may be symptom-free if they don't move.
  
• Benign paroxysmal positional vertigo (BPPV): BPPV may be caused when the crystals in the inner ear become dislodged and irritate the semicircular canals. Often the cause is not found, but there may be an association with unusual positioning or movement of the head, for example, moving the head up and down while working on a computer. It is frequently seen in people older than 60 years of age.
  
• Labyrinthitis: Labyrinthitis (labyrinth=inner ear + itis=inflammation) may follow a viral infection which causes inflammation within the middle ear.
  
• Meniere's disease: This condition is a disorder of the flow of fluids of the inner ear; symptoms include vertigo, hearing loss, and tinnitus (ringing in the ears).
  
• Acoustic neuroma: This is a benign tumor of the ear that can be present with vertigo.
  
• Brain: Much less commonly, the cause of vertigo may arise in the brain. Stroke, tumors, seizures and multiple sclerosis may be associated with vertigo.

What are the symptoms experienced when a person feels dizzy?

• Lightheadedness is the feeling of weakness and faintness as if you are about to pass out. The symptoms tend to be short-lived, depending on the cause. There may be associated nausea, sweating, and blurred vision.
  
• If the cause is dehydration or bleeding, the symptoms may be brought on by standing quickly and may resolve somewhat by lying down (orthostatic hypotension)
  
• Heart rhythm disturbances may occur without warning and may be associated with palpitations. This may come and go or it may persist. The heart beat may be felt as too fast (often described as a pounding), too slow, and/or irregular.
  
• Vertigo is the sensation of spinning and may present without warning and be associated with nausea and vomiting. People with inner ear problems may be unable to move without generating symptoms.
  
• People with a cerebellar cause of vertigo such as a stroke or tumor may have associated coordination problems or difficulty walking.

When should I call the doctor for dizziness?

Dizziness is a common complaint and often has resolved by the time the patient arrives to see a health care practitioner. Usually there is no rush to seek care. However, while the complaint of dizziness is not often an emergency, care should be sought immediately if it is accompanied by any of the following:

• Chest pain, shortness of breath, or palpitations. These symptoms should not be ignored as they suggest the heart may be the source of the dizziness.
  
• Dehydration. Often there may be an associated illness including fever, vomiting, or diarrhea.
  
• People with diabetes may have dizziness due to low blood sugar (hypoglycemia) or high blood sugar (hyperglycemia), and may need emergent care to stabilize their insulin and medication requirements.
  
• Bleeding from any source.
  
• Altered mental status or thinking. This may include symptoms such as confusion, change in vision, change in speech, facial droop, weakness of one side of the body, or headache. These may be signs of stroke, bleeding in the brain, or tumor.
  
• Vertigo may cause significant problems with vomiting and may be debilitating. Often, medical care is needed to control symptoms even though the underlying problem is not serious.

How is dizziness diagnosed?

The diagnosis of dizziness begins with the health care practitioner evaluating whether the complaint of dizziness refers to lightheadedness or vertigo. Further direction continues once this distinction is made.

The key to the diagnosis of dizziness is a thorough history and physical examination. Often the diagnosis is made by listening to the patient's story. The health care practitioner may ask about triggers that cause and relieve the symptoms of dizziness, such as:

• "Is it related to changing positions quickly?" and
• "Does it resolve on its own or does the patient have to do something, like lie down to make it better?"

A review of systems is a series of questions that review the patient's body functions. Questions may be asked about associated symptoms including fever, vomiting, diarrhea, chest pain, shortness of breath, palpitations, or abnormal bleeding. The past medical history may be reviewed, and this includes reviewing  medications the patient is currently taking.

A thorough physical examination will likely be done, this may include:

Vital signs: Taking the patient's blood pressure and pulse rate lying down and standing (called orthostatic or postural vital signs) often will indicate the fluid status of the body. In patients who are dehydrated or bleeding, the vital signs may rise on changing position. However, patients taking medications such as beta blockers will not generate in increased pulse rate.

Tailored physical examination: Often, the physical examination is tailored to the patient based upon the information provided in the patient's medical history. For example, a woman with a heavy menstrual period may need a pelvic examination, or a patient with cough and shortness of breath may need a closer examination of the heart and lungs.

Imaging studies and blood tests: The need for imaging studies and/or and blood tests will depend on the concerns the health care practitioner and patient have in regard to the cause of the dizziness. Common tests that may be ordered include:

• complete blood count (CBC) to screen for anemia or infection,
  
• evaluation of electrolytes,
  
• blood sugar tests,
  
• kidney function tests, and
  
• thyroid tests.

X-rays, CT scans, and MRI may be indicated depending upon the patient's needs.

How is vertigo diagnosed?

The diagnosis of vertigo is most often made based upon history and clinical presentation. If the patient is experiencing a spinning sensation that worsens by a change in position, and lessens by lying still, the health care practitioner can confirm the cause of dizziness as vertigo.

Further history may be taken to make certain that the symptom of vertigo is isolated to an inner ear condition and not due to a problem in the brain (for example, a stroke).

Neurological examination

Physical examination will focus on the neurologic examination and may involve looking at eye movements. With vertigo, nystagmus may be present. This is an involuntary movement of the eyes, slow and smooth in one direction with fast twitches in the other. It is the eyes' attempt to compensate for the abnormal signals being created in the inner ear.

The patient's hearing may be tested to assess potential hearing loss. This may be seen in Meniere's Disease or with an acoustic neuroma, but not necessarily with labyrinthitis or benign positional vertigo.

The rest of the neurologic examination may be done to look for one-sided weakness, loss of coordination, or loss of balance as potential signs of stroke.

Evaluation for BPPV or labyrinthitis is often complete at this point, although depending upon the health care practitioner's concerns, further testing may be indicated. Referral may be made to a physical therapist specially trained in vestibular therapy.

If there is confusion as to the potential cause of vertigo, imaging of the brain may be needed. Magnetic resonance imaging (MRI) may be indicated since this test evaluates the cerebellum more accurately. Computerized tomography (CT scan) may be used in an emergency to assess bleeding

How is dizziness treated?

Dizziness treatment

Dizziness is a symptom, not a disease, and treatment will be directed to the underlying cause. For example, dizziness or lightheadedness due to dehydration from gastroenteritis may require intravenous fluids and medications to stop the vomiting and diarrhea, while dizziness or lightheadedness from a heart rhythm condition may require admission to the hospital and specialized testing and treatment.

Vertigo treatment

• Vertigo from inner ear problems may often be treated with maneuvers to reposition the crystals and debris in the semicircular canals.
  
• Depending upon the reason for the inner ear inflammation, oral steroid medications to decrease that inflammation might be prescribed.
  
• Over-the-counter or prescription medication is occasionally recommended or prescribed to help with vertigo. Meclizine (Antivert) may help with control of mild symptoms.
  
• In patients with intractable symptoms and vomiting, intravenous diazepam (Valium) may be considered.
  
• Patients with Meniere's Disease or acoustic neuroma are usually referred to an ear, nose, and throat specialist (otolaryngologist, ENT physician) for further evaluation and care.

Dizziness At A Glance

• Dizziness is a symptom that is often applies to a variety of sensations including lightheadedness and vertigo. Vertigo is the sensation of spinning, while lightheadedness is typically considered near fainting, and weakness.
  
• Conditions that may cause dizziness in a patient include low blood pressure, high blood pressure, dehydration, medications, postural or orthostatic hypotension, diabetes, endocrine disorders, hyperventilation, heart conditions, and vasovagal syncope.
  
• Vertigo is most often caused by a problem in the balance centers of the inner ear called the vestibular system and causes the sensation of the room spinning. It may be associated with vomiting. Symptoms often are made worse with position changes. Those with significant symptoms and vomiting may need intravenous medication and hospitalization.
  
• Vertigo is also the presenting symptom in patients with Meniere's Disease and acoustic neuroma, conditions that often require referral to an ENT specialist.
  
• Most often, dizziness or lightheadedness is a temporary situation that resolves spontaneously without a specific diagnosis being made.