Prognosis

An estimated 450,000 American adults are admitted to an emergency room with asthma each year. The number of deaths from asthma increased from about 2,900 in 1908 to a high of 5,667 in 1996. The numbers appear to be declining slightly, and in 2002 about 4,260 people died because of asthma. Death from asthma is still a very uncommon event, considering that an estimated 20 million people in the U.S. have this condition. Most deaths from asthma, even when they occur in elderly adults, are preventable. It is very rare for a person who is receiving proper treatment to die of asthma. And studies suggest that the use of inhaled corticosteroids can reduce the risk for death by 90%. In spite of this and similar research, these important drugs are greatly underused.

Risk Factors for Very Severe or Fatal Asthma

About 55% of U.S. deaths from asthma occur among the elderly (over age 65), and an estimated 25% occur in adults aged 45 to 64. Women have a higher risk for fatal asthma than men. Being poor is also a significant risk factor for severe asthma. Hispanics and African Americans are at higher risk for death from asthma than Caucasians. Other specific risk factors for fatal asthma include:

  • Previous history of respiratory failure
  • Frequent visits to the emergency room
  • Lack of continuous care and poor compliance with medications
  • Having stopped treatment, particularly withdrawal from corticosteroids
  • Having an emotional or psychiatric disorder. (Some evidence suggests that depression, anxiety, and stressful life situations can worsen asthma.)
  • Being a drug abuser
  • Being in a lower socioeconomic and educational group

Symptoms of a Life-Threatening Attack

The following signs and symptoms may indicate a life-threatening situation:

  • As the chest labors to bring enough air into the lungs, breathing often becomes shallow.
  • Lacking sufficient oxygen, the skin becomes bluish.
  • The flesh around the ribs of the chest appears to be sucked in.
  • The patient may begin to lose consciousness.

Asthma often progresses very slowly to a serious condition or may develop to a fatal or near-fatal attack within a few minutes. It is very difficult to predict when an attack will become very serious.

It should strongly be noted that early symptoms or lack thereof do not always reflect the ultimate severity of an attack. In fact, some studies suggest that people at high risk for fatal or near-fatal asthma attacks are those with poor awareness of their own reduced ability to breathe and who are therefore slow in seeking help. Those at highest risk for this effect tend to be older, female, and have had the disease for a longer period of time.Monitoring peak flow rates is an important management component since it provides a more accurate assessment of lung function than symptoms alone.

Degree of Severity

The severity of asthma is graded using the following categories: mild intermittent and mild, moderate, and severe persistent. A patient in any of these categories, even mild intermittent, can still experience a severe and even life-threatening attack. In fact, according to one report, 30% of asthma deaths occur in patients with mild asthma.

Long-Term Outlook

Asthma is usually chronic, although it occasionally goes into long periods of remission. Long-term outlook generally depends on severity:

  • In mild-to-moderate cases, asthma can improve over time, and many adults even become symptom free.
  • Even in some severe cases, adults may experience improvement depending on the degree of obstruction in the lungs and the timeliness and effectiveness of treatment.
  • In about 10% of severe persistent cases, changes in the structure of the walls of the airways lead to progressive and irreversible problems in lung function, even in aggressively treated patients.

Lung function declines faster than average in people with asthma, particularly in those who smoke and in those with excessive mucus production (an indicator of poor treatment control). Overall, one study reported that 72% of men and 86% of women with asthma had symptoms 15 years after an initial diagnosis. Only 19% of these people, however, were still seeing a doctor, and only 32% used any maintenance medication.

Patients who develop occupational asthma often experience asthmatic symptoms for years, even after avoiding the harmful triggers. Improvement does occur over time in most people who leave such jobs.

Miscellaneous Complications or Associations

Emotional Problems. Even when it is not life threatening, asthma is debilitating and frightening. It significantly lowers the quality of life.

Sleep Disorders. Sleeplessness and daytime sleepiness are common problems. Studies indicate that between 80 - 93% of people with asthma have sleeping problems about three times a week. In one poll, 40% missed work an average of 11 days a year because of sleep disturbance. Asthma has been associated with snoring and obstructive sleep apnea, a condition in which blockage of the upper airway causes the sleeper to temporarily stop breathing, then resume with a gasp, often many times during each hour of sleep.

Asthma and Pregnancy. Uncontrolled asthma in pregnant women puts them at higher risk for complications that can include early labor, hypertension, gestational diabetes, and hemorrhage. Asthma also places the babies at risk for lower birth weight and breathing disorders. Teenage mothers with asthma face higher risks than older women. Fortunately, studies indicate that most asthma drugs are safe to take during pregnancy, and good control of asthma reduces these risks to normal levels.

New guidelines released in 2005 by the National Asthma Education and Prevention Program (NAEPP) emphasize that most asthma medications are safe for pregnant women. The guidelines recommend that pregnant women with asthma have albuterol available at all times. Inhaled corticosteroids should be used for persistent asthma. Patients whose persistent asthma does not respond to standard dosages of inhaled corticosteroids may require a higher dosage or the addition of a long-acting beta agonist to their drug regimen. For severe asthma, oral corticosteroids may be required. The NAEPP notes that while it is not clear if oral corticosteroids are safe for pregnant women, uncontrolled asthma poses an even greater risk for a woman and her fetus. 

Heart Disease. There have been some reports of an association between asthma and a heightened risk for heart disease. Some experts believe that the inflammatory process may be the common factor linking the two conditions, although there is no evidence to date confirming any causal association.

Review Date: 3/18/2006
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.