 And decades of research shows all this loneliness can pose serious health risks. Patel says illnesses linked to loneliness include heart disease, stroke, high blood pressure, and mental illness. One researcher said, and I quote, loneliness is a fertilizer for other diseases to grow on. So what to do? Try online support groups, share positive emotions with people. That also helps. Talk to strangers, practice self-care, or hey, start a hobby. Sarah Jacobs, WTOP News.