Usually, strong emotions come and go, and normal physiological equilibrium is restored. But when emotional stressors endure for long periods of time, they can tip the balance of chemicals in brain and body and affect your health, often for the worse. Learning to recognize the physiological consequences of your emotions, and finding ways to establish emotional balance in your life, can help you avoid many health problems that may result from the way you react to the world around you.

Consider susceptibility to the common cold, for example. A study published in the November/December 2006 issue of the journal Psychosomatic Medicine suggests emotional factors can affect resistance to cold and flu symptoms. Researchers interviewed 193 healthy volunteers daily for two weeks about the positive and negative emotions they had experienced each day, recording the results. They then exposed subjects to a cold or flu virus. Fewer positive-thinkers became infected, and positive thinkers who did become infected had less pronounced symptoms than subjects with more negative emotions. Only 28% of infected individuals who often reported positive emotions developed symptoms such as cough or congestion, compared to 41% of those who rarely reported positive emotions.

“Positive emotions are thought to be beneficial to health,” said Darin D. Dougherty, MD, Massachusetts General Hospital. “But when we experience negative emotions in excess, they can be physically and psychologically harmful. Chronic excess anger, for example, is linked to a higher risk of hypertension, diabetes and heart disease. For this reason, it’s important to strive to stabilize your emotions. “The good news is that we can minimize health problems associated with emotional stressors by seeking out circumstances that make us feel positive, avoiding as much as possible situations that cause us distress, and by using stress reduction techniques to address the stresses that we can’t control.”

The Body-Mind Interface
Emotions are conscious mental states that arise spontaneously in reaction to situations (or memories of situations) in the environment, and usually manifest themselves in behavioral and physiological changes. Emotions have evolved to help us defend ourselves (anger), bond with others (joy and love), and avoid danger (fear), among other things, and are important for human survival. Responses to emotion-evoking events that involve conscious thought are generated within the cortex, a region of the brain responsible for reasoning, voluntary muscle movement, and memory. Even more rapid reactions occur without conscious control. This is the work of the limbic system, a network of brain regions involved in many primary emotions. It responds to emotional triggers by activating the autonomic nervous system, which controls the automatic functions of the body, such as circulation, digestion and respiration. The autonomic nervous system physically prepares the body for action when necessary, and helps restore a normal, relaxed state when the need for action passes. The limbic system generates physiological and behavioral responses to emotions that are stereotypic patterns displayed by every human being. These responses often involve outward manifestations of emotion, such as facial expressions and muscle tightening. The patterns—such as the downcast facial expression of sadness—are so universal we recognize them in others. But many physical and behavioral effects generated by the limbic system may be hidden from view inside our bodies. These include responses to emotion such as increases in heart rate and blood pressure, constriction of blood vessels, and gastrointestinal disturbances.

Physical Fallout
The intensity of emotional responses and their effects on the body can be influenced by a number of physiological factors, including patterns of brain activation, levels of hormones, levels of brain chemicals called neurotransmitters, and patterns of autonomic nervous system activity. Research suggests that each emotion is associated with a characteristic set of physiological responses. Here are examples of common emotions, along with some observed physical consequences:

Anger: Increase in diastolic blood pressure, heart rate and cardiac output; changes in respiration; dilation of blood vessels (flushing); dilation of pupils and tearing of eyes; tensing of muscles; hyperactivity (pacing, tapping feet, etc.); focused vision; sweating; stimulation of upper gastrointestinal (GI) contractions and acid secretion; suppression of immune response.

Fear/anxiety: Increase in systolic blood pressure, heart rate, and cardiac output; constriction of blood vessels (pale skin); increased muscle tension; changes in respiration; tightening of throat; trembling; light-headedness; shortness of breath; sweating; nausea; inhibition of contractions and secretions of the upper GI tract (feelings of lack of appetite and fullness); stimulation of the motility and secretions of the lower GI (abdominal pain and diarrhea); suppression of immune response.

Shame/guilt: Flushing or warmth in the upper chest and face; irregular breathing; increased pro-inflammatory activity; increased vulnerability to stress.

Joy/pleasure: Slowing of heart rate and respiration, lower blood pressure.

Sadness/grief: Tightness in throat and eyes; relaxation of arm and leg muscles; increased heart rate and elevated blood pressure; shortness of breath; insomnia; pain; gastrointestinal symptoms; fatigue; headache; chest pressure; backache; dizziness; suppression of immune response.

Disgust: Slowed heart rate; nausea; increased salivation.

Loneliness: Sleep disturbance; lack of appetite; reduced energy; headaches or stomach pain; high blood pressure; elevated stress hormones.

Love/desire: Slowed heart and respiration rate; muscle relaxation; enhanced immune response. When intense (love sickness), can be associated with dry throat, increased respiration; changes in appetite, and sleep disturbance.

Humor/laughter: Release of tension; lowered blood pressure, heart rate and respiration rate; elevated immune response; improved pain tolerance; increased levels of endorphins resulting in improved mood.

Emotional Damage Control
When emotional stressors such as anger or loneliness affect the body repeatedly, or over a long period of time, they can compromise the health of vulnerable individuals. Such prolonged stress is associated with a variety of disorders, including metabolic syndrome (a precursor to type 2 diabetes characterized by insulin resistance, hypertension and elevated levels of unhealthy LDL cholesterol), cardiovascular problems, confusion, poor memory, allergies, ulcers, functional bowel disorders, insomnia and rapid aging. Fortunately, you can reduce your risk of health problems associated with emotional wear and tear by paying attention to your emotional reactions and taking steps to establish emotional balance. Minimize emotional stress by buffering yourself from upsetting situations as much as possible. Adopt a positive attitude toward life. Pursue activities that you enjoy, and seek out people with whom you can be yourself. To build up resilience, eat a nutritious diet, avoid drugs, limit alcohol, exercise, get adequate sleep, and take time to relax. “If you find you can’t manage your emotions on your own, it’s important to get help,” Dr. Dougherty says. “There are effective therapies available that can help you reduce unhealthy stress and restore a sense of calm and control to your life.”