“The Heart is a Lonely Hunter,” a novel by Carson McCullers, is about an isolated deaf man who strives to build friendships with four acquaintances.

Each of the book's main characters is equally lonely for different reasons: physical and intellectual deficits, political beliefs, lack of education, or loss of a loved one.

Written nearly 80 years ago, the novel still resonates today. According to a survey, one in five Americans say they always or often feel lonely or socially isolated — and that takes a toll on personal health.

Other studies have linked chronic loneliness to migraines, high blood pressure, diabetes, pain, gastrointestinal problems, chronic inflammation and stress, insomnia, and poor or disordered eating habits.

In fact, people who are chronically lonely are 50% more likely to die prematurely than those who feel supported by friends, family, and community.

No wonder research suggests loneliness can be as harmful to a person as smoking 15 cigarettes a day.

If you often feel lonely or isolated, it's smart to seek professional help to identify the causes and explore solutions.

Social anxiety? Physical disability? Loss of resources? Death of a partner or companion? This may sound basic, but go outside and move around. Sunshine, physical activity, and being around people (even strangers) can have restorative benefits.

Volunteer to help others, or join a cooking, pottery, or yoga class.

Finally, use the Internet to find organized groups to join (in person or online) that align with your interests.

You'll be surprised by how many people are looking for exactly the same thing.