People who experience generalized anxiety disorder (GAD) exhibit excessive concern about multiple events or activities most days of the week. While it is not unusual for people to experience some stress as they go about their daily lives, GAD sufferers rarely get a break from worrying.

Although some of the symptoms and reactions may be similar to those of a phobia (an extreme, irrational fear), GAD is not a direct response to a specific situation or experience. Sufferers experience unease that casts a shadow over all of their activities.

While not nearly as intense as a panic attack, the unease lasts much longer and almost doesn't let up, according to the National Institute of Mental Health (NIMH).

GAD affects about 6.8 million American adults, and strikes twice as many women as men, according to the Anxiety and Depression Association of America (ADAA).That translates to about 3.1 percent of the adult population suffering from the disorder, and about one-third of those cases can be classified as severe.

Symptoms of GAD

Though people who suffer from GAD worry about the same things that other people do — relationships, money, health, work, etc. — they have a much higher level of worry that is nearly constant. The level of concern is not in sync with reality and is greatly magnified. Most people with GAD realize that their concerns are overblown, but they cannot seem to shake their anxiety, according to the NIMH.

Duffey said GAD patients are aware that their anxiety level is highcompared to that of others, but they feel shame and embarrassment to address the problem. "They know better, but they can't help the negative thoughts," she said.

Both children and adults can develop GAD, and symptoms can come on slowly, according to the Mayo Clinic. But in some instances, a major life event, such as a change in health, or a life transition such as a divorce, can trigger the onset of GAD, Duffey told Live Science. 

"GAD patients have always been anxious to some degree, but an event such as a car accident, poor grades, relationship or work difficulties can enhance their anxiety," she said. 

The symptoms tend to ebb and flow but can be exacerbated during times of stress. What sets the worry of GAD suffers apart from normal stress is that the worry is intrusive, excessive, debilitating and persistent — lasting for more than six months, according to the NIMH. 

Fatigue, nausea, muscle tension, nervousness, sweating, irritability and trembling are some of the physical symptoms of GAD, according to the Mayo Clinic.

Sleeplessness is another sign of GAD, because people with the disorder often feel as if they can't stop their mind from racing, Duffey said. People with GAD can also be very indecisive or have a fear of making the wrong decision, can overthink and have difficulty concentrating or have the feeling that their minds are "going blank"

Like those with panic disorder, GAD sufferers have difficulty with everyday tasks, the NIMH noted. However, people with GAD are not gripped by an overwhelming fear and are typically able to function. However, some may be unable to perform even routine tasks during times when their symptoms are the worst, according to the NIMH. 

Causes

GAD may run in families, although as with all mental-health issues, the causes are typically a combination of biological and environmental factors, according to the Mayo Clinic. 

"It is likely due to a combination of stress and environmental factors that contribute to the expression of genes in individuals who are born with the risk/vulnerability to develop the condition," said Dr. Andrew Gilbert, a psychiatrist and medical director at the Hallowell Center in New York. "Since GAD can emerge in adolescence, there are some interesting developmental/pediatric studies suggesting that individuals born with particular temperaments and/or wiring in their brains may be more vulnerable to develop GAD."

An imbalance of naturally occurring brain chemicals — such as serotonin, dopamine and norepinephrine — is often seen in people with GAD and could be an indicator of a propensity to develop the disorder, according to the Mayo Clinic. An imbalance of these chemicals, called neurotransmitters, can impact emotional stability and mental well-being. 

Enduring a trauma, especially during childhood, is also linked to GAD, according to the Mayo Clinic. Those who experienced abuse or trauma as a child, including witnessing a traumatic event, are at higher risk of developing generalized anxiety disorder.

Connection to addiction

Those with anxiety disorders are two to three times more likely than the general population to abuse alcohol or other substances at some point in their lives, according to the ADAA. About 20 percent of Americans with an anxiety or mood disorder, such as depression, have an alcohol or other substance-abuse disorder, according to the ADAA.

GAD sufferers are cautioned to avoid alcohol and drug use, even nicotine and caffeine, which can increase anxiety, according to the Mayo Clinic. However, as quitting can also cause anxiety, they recommend you see a doctor for a treatment program or support group that can help.

Treatment

GAD can be treated with psychotherapy, medication or both, according to the NIMH.

A type of psychotherapy called cognitive behavioral therapy (CBT) is a common method used to treat GAD and can be very helpful, according to the NIMH. This therapy teaches a patient new ways of thinking, behaving and reacting to situations.

"Numerous studies have found CBT effective treatment for GAD in children, adolescents and adults," Gilbert said. 

Many GAD sufferers also benefit from self-help and support groups, where they can share their challenges and discuss coping mechanisms, according to the ADAA. 

Various types of medications can also be useful for treating GAD, including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).

Duffey said that while medication can be helpful for some GAD patients, she advocates for treatment that emphasizes lifestyle factors, such as nutrition, exercise and establishing a routine. 

"I focus on knowledge, as knowledge is power and can provide a sense of hope and safety, as well as self-empowerment and self-acceptance," Duffey said. 

"Don’t give up on treatment too quickly. Both psychotherapy and medication can take some time to work, " the NIMH website states. "A healthy lifestyle can also help combat anxiety. Make sure to get enough sleep and exercise, eat a healthy diet, and turn to family and friends who you trust for support."

This article is for informational purposes only and is not meant to offer medical advice. This article was updated on Nov. 6, 2018 by Live Science Staff Writer, Yasemin Saplakoglu.