Stress and Your Health: What the Research Says

By Vince Tornambe, Certified Developmental Alphabioticist, Brain Reboot San Diego, Poway.

Do you ever lie awake at 2 a.m. going over tomorrow's list, even though nothing is wrong right now? Plenty of people do. The stress statistics on this page come from large surveys and published studies, and they show how common that feeling is and what it's linked to in the body.

In Gallup's 2025 data, 36% of adults worldwide said they felt a lot of stress during much of the previous day, and half of U.S. employees said the same. Stress that keeps running is linked to a higher risk of heart disease and stroke, weaker immune responses and slower recovery from wounds. Each figure below names its source, and the full list is at the end.

Stress statistics: how common is stress?

Gallup's World Poll asks adults in about 140 countries whether they felt a lot of stress during much of the day before. In 2024, about 37% of adults worldwide said they felt a lot of stress during much of the previous day, and the figure was 36% in 2025 (Gallup, 2025; 2026).

Work pushes the number up. Half of U.S. employees said they felt a lot of stress during much of the previous day, compared with 40% of employees worldwide (Gallup, 2026). The U.S. figure is a three-year average.

The American Psychological Association asks the question another way, as a number. About one in four U.S. adults (24%) rated their average stress 8 to 10 on a 10-point scale in 2023, up from 19% in 2019 (APA, 2023).

What does stress do to your body day to day?

In the APA's 2022 survey, 76% of U.S. adults said stress had affected their health in the past month, most often as headache (38%) or fatigue (35%) (APA, 2022). Sleep takes a hit. In the APA's 2012 survey, 43% of U.S. adults said stress had kept them lying awake at night in the past month (APA, 2013).

Muscles respond too. In a lab study of 62 women, mental stress tasks alone, such as mental arithmetic, raised tension in the upper trapezius, the muscle that runs from the neck across the top of the shoulder (Lundberg et al., 1994). If your shoulders feel tight after a hard afternoon at a desk, that's the muscle in question.

The World Health Organization's stress leaflet lists the physical signs as headaches or dizziness, muscle tension or pain, stomach or digestive problems and a faster heartbeat (WHO, 2023). If any of these keep coming back, check in with your doctor.

Why does stress stay with you after the moment passes?

Harvard Health describes the stress response with a car. Your body has a gas pedal and a brake, and both are always working. Stress presses the gas harder; rest gives the brake more say. The gas pedal is the sympathetic nervous system, the fight-or-flight side. The brake is the parasympathetic side, often called rest and digest (Harvard Health Publishing, 2024; Berntson et al., 1991). When stress is low but constant, Harvard says it keeps the system running like a motor that is idling too high for too long.

You don't need a crisis to keep that motor running. A review of 60 studies found that worry about the future and going over the past are linked to higher blood pressure, a faster heart rate, more cortisol and lower heart rate variability, even when nothing is happening in the moment (Ottaviani et al., 2016). That's the 2 a.m. list from the top of this page. We call this state protection mode: the body braced and ready for a threat that isn't in the room.

Stress and your heart

The heart has some of the largest studies behind it. The INTERHEART study compared 11,119 people who'd had a first heart attack with 13,648 people who hadn't, in 52 countries. It found that people who had a heart attack were about twice as likely as matched controls to report constant stress at work or home in the past year (Rosengren et al., 2004).

Studies that follow people forward in time point the same way. People with high perceived stress had a 27% higher risk of developing coronary heart disease than people with low perceived stress, across six studies and 118,696 adults (Richardson et al., 2012). At work, people with job strain, meaning high demands and little control, had a 23% higher risk of a first heart attack or coronary death in a study of 197,473 European adults (Kivimäki et al., 2012). For the brain's blood supply, pooling 14 studies, people exposed to general or work stress or stressful life events had a 33% higher risk of stroke (Booth et al., 2015).

If your heart or blood pressure is on your mind, keep working with your doctor. These numbers are a reason to have that conversation, and nothing here replaces it.

Stress and your immune system

A review of more than 300 studies found that long-lasting stress was linked to weaker immune responses of several kinds, while very short stress can briefly ramp some defenses up (Segerstrom and Miller, 2004). The stress response is built for short bursts.

One of the best-known experiments gave healthy volunteers cold viruses on purpose and tracked who got sick. Those under more stress were more likely to catch a cold, rising from about 27% to 47% (Cohen et al., 1991).

Stress and the body's repair work

Pooling 11 studies, higher stress was consistently linked to slower or poorer wound repair (Walburn et al., 2009). A small study of 26 women shows what that looks like. Women caring for a relative with dementia took about 9 days longer for a small standard skin wound to close than similar women who were not caregivers (Kiecolt-Glaser et al., 1995).

Wear and tear over time

Researchers have a name for the load that builds up when stress keeps running: allostatic load, a score of wear and tear across the body systems that handle stress. In the MacArthur studies of aging, older adults with a higher allostatic load score had more decline in thinking and physical function and more cardiovascular disease (Seeman et al., 1997).

The body is built to settle

The body can come back down quickly once a threat ends. In one experiment, 50 young men were told an unavoidable painful shock was coming. Their adrenaline, pulse, tension and natural-killer immune cells rose within minutes, and when the threat was removed these returned to baseline just as quickly (Breznitz et al., 1998).

How fast that return happens isn't the same for everyone. After a short lab stress task, men in lower-grade jobs had inflammation (IL-6) that kept rising for 2 hours and heart rates that were slower to settle than men in higher-grade jobs. By 2 hours, 75% of the higher-grade men were back to their resting heart rate, compared with 38.1% of the lower-grade men (Brydon et al., 2004). A spike in stress is normal. A slow return to calm, day after day, is the part that adds up.

How we look at stress in Alphabiotics

Alphabiotics has its own way of describing where long-running stress leads. In the Alphabiotic view, unrelieved stress leads to weakness, then tension, then imbalance, and over time to degeneration and disease. That chain is the founder's model, and it shapes how we look at stress in the studio.

An Alphabiotic Alignment is gentle, hands-on and brief. It was developed in the 1920s, and it's intended to support balance between the brain's hemispheres and help the body release stress. You lie on your back, and it's a gentle, quick movement of the head, under about 15 seconds, with a check of your leg length and power, hip height and rotation, arm length and power, and the rotation of and tension in your neck before and after.

If you're dealing with pain, an injury or a medical condition, keep working with your doctor. This isn't a replacement for that care. It's one more option to explore alongside it.

More on stress and the body

• The Bear and the Bills: Why Your Body Keeps Bracing

• The Stress You Stop Noticing

• Gas Pedal and Brake: How Your Nervous System Really Works

• It's Not the Spike, It's the Recovery

• When Worry Follows You to Bed

Try one visit

If you'd like to try it, one visit is a simple place to start. If you'd like to know what happens first, the Your First Visit page walks through it.

Book your first visit at brainrebootsd.com/book or call (858) 354-8153.

Brain Reboot San Diego offers complementary wellness experiences. Alphabiotics does not diagnose, treat, or cure medical conditions and is not a substitute for medical care.