9 Illnesses That Stress May Cause or Make Worse
Chronic stress certainly doesn’t help or promote healing in any disease or health problem. Here are some common illnesses that can be caused and made worse by stress.

1. Depression and Other Mental Health Conditions
The exact reason why some people experience depression and anxiety as clinical mood disorders and others do not is still unknown, according to the Centers for Disease Control and Prevention (CDC). Many factors are potentially in play, including genetic, environmental, and psychological conditions, as well as major stressful or traumatic experiences.

Research shows, however, that chronic stress left unmanaged is linked to serious mental disorders like anxiety and depression. Persistent or prolonged stress leads the body to produce certain hormones and chemicals that perpetuate an ongoing state of stress that can have adverse effects on key organs.
Around 20 to 25 percent of persons who experience major stressful events will go on to develop depression, according to a commentary and review of research published in JAMA.

2. Insomnia
An informal APA survey from 2013 on stress and sleep found links in both directions. Forty-three percent of the nearly 2,000 adults surveyed reported that stress had caused them to lie awake at night at least one time in the past month. When they didn't sleep well, 21 percent reported feeling more stressed. Among adults with higher self-reported stress levels (8 or higher on a 10-point scale), 45 percent said they felt more stressed when they didn’t get enough sleep. Finally, adults with lower self-reported stress levels claimed they slept more hours per night on average than adults with higher self-reported stress levels, to the tune of almost an hour less sleep (6.2 versus 7.1 hours a night).

3. Cardiovascular Disease
Chronic stress has long been connected to worsened heart health outcomes. While there’s limited conclusive evidence to say that stress alone can trigger heart disease, there are quite a few ways stress contributes to it, according to a JAMA review. Part of the stress response is a faster heart rate and blood vessel constriction (or vasodilation for some skeletal muscles to help the body move in a fight or flee response), thanks to the stress hormones adrenaline, noradrenaline, and cortisol, according to research. If the body remains in this state for a long time, as in chronic stress, the heart and cardiovascular system may be damaged, according to other research.

Another means by which stress can contribute to heart disease: You might cope with your stress by eating or drinking too much, which in turn can contribute to cardiovascular disease, also according to APA.

“Negative emotions and stress can contribute to a heart attack,” Dr. Dossett says. One meta-analysis, for example, found a 50 percent increased risk of cardiovascular disease associated with high levels of work stress.

4. Common Cold
Stress can also weaken your immune function, which can make you more susceptible to infectious diseases like colds, Uchino explains. Researchers conducted an experiment in which they exposed a group of 420 volunteers to the common cold virus and then quarantined them to see if they got sick. The data revealed that participants who suffered from greater overall stress at the start of the study (measured via surveys on stressful life events, perceived stress, and mood) were more likely to become infected with a virus after exposure.

5. HIV and AIDS
Stress does not cause HIV (the virus that causes AIDS, which is sexually transmitted or passed through blood, which can happen when needles are shared). But there is some evidence that stress can worsen severity of the disease. A study of 177 HIV-positive patients found that the stress hormone cortisol (associated with chronic stress) was linked to a higher HIV viral load over four years and accelerated disease progression in people living with HIV. For the study, cortisol levels were measured via urine samples every six months.

Another review, published in 2016, concluded that while the link between stress and clinical outcomes is unclear, higher stress was linked to lower disease-fighting white blood cell counts, higher viral load, and disease worsening. Studies also linked stress with worse treatment adherence, per the review.

6. Gastrointestinal Disease
“Stress can affect gastrointestinal motility,” says Dossett, which is how food moves through your digestive system, increasing your chances of irritable bowel syndrome, inflammatory bowel conditions, gastroesophageal reflux, constipation, diarrhea, and discomfort. “All those things can be impacted by stress,” she says.

Research supports this as well.

7. Chronic Pain
Some chronic pain conditions like migraine and lower back pain can be caused, triggered, or worsened when body muscles tense up. A lot of chronic low back pain is related to stress, says Dossett. “Very often it’s muscle tension and tightness that is pulling or creating strain, and then contributing to this sensation of pain.”

A study published in 2021 confirmed a strong relationship between the degree of stress and chronic lower back pain. The researchers concluded that clinicians who treated patients with chronic low back pain should also evaluate a patient’s stress levels.

“Pain is inherently stressful. When the pain does not appear to be remitting or getting better, the concern regarding the pain can turn into fear, anxiety, and hopelessness,” says Joel Frank, PsyD, a psychologist in private practice in Sherman Oaks, California.

A review published in 2017 examined the overlap between chronic stress and chronic pain, finding that both conditions triggered similar responses in the brain, particularly in the hippocampus and amygdala. The researchers also noted, however, that because of the wide variety of ways humans experience chronic pain and stress, these two conditions do not always overlap.

8. Cancer
What causes cancer is a particularly challenging question to answer, says Uchino. Because most patients are diagnosed only after years of cancer cell growth, it’s difficult if not impossible to pinpoint a specific cause. And it’s likely that several factors (someone’s genes, plus an environmental trigger like smoking, air pollution, or stress, for example) contribute.

But there is some evidence in human studies that stress plays a role in the onset of cancer, Uchino says. (It’s also worth noting that some studies have found no link.)

One possible reason why stress might contribute to some cancers: Stress can activate your brain and body’s inflammatory response, as well as stimulating your adrenal glands to release stress hormones called glucocorticoids, among many other downstream effects. Some research suggests that too much of this type of inflammation from chronic stress is the connection with cancer (as well as some autoimmune diseases — see below), Dossett explains.

9. Autoimmune Conditions
“Many inflammatory conditions are exacerbated by stress, and that includes autoimmune conditions like multiple sclerosis, rheumatoid arthritis, lupus, psoriatic arthritis, and psoriasis,” says Dossett. A Swedish population-wide study published in the June 2018 issue of JAMA found that patients with a stress disorder were more likely to develop an autoimmune disorder (9 per 1,000 patients per year compared with 6 per 1,000 among those without stress disorders).

Another extensive review on the role of stress in autoimmunity emphasized that this is a relationship that often overlooks.