You can't get far in life without a little stress. The shaky feeling you get before a job interview? That's stress. Those jangly nerves that make you stammer when asking for a date? That's stress talking. And the feeling of elation you get when you actually land that job or that date despite yourself? Welcome to Stress City.


 


Any shift away from ordinary, everyday life whether the change is positive or negative may cause stress. When there's a break in your routine, your brain often sounds an alarm by releasing "stress hormones" such as adrenaline and cortisol. These hormones are more than just alarm bells; they're potent chemicals that have a striking impact on the entire body. They make your heart pound faster and speed up your breathing, a one-two combination that primes your muscles for action (In a real emergency, your blood flow can increase up to 400%). The hormones also slow down the digestive system and parts of the immune system. In a crisis, the body has more important things to do than digest lunch or fight a few germs.


 


A small dose of stress hormones can give you the energy you need to meet a tight deadline or make a speech. A larger dose could save your life. If somebody runs up behind you on a dark sidewalk, you'll get a mega-burst of adrenaline to help you either run like mad or turn around to defend yourself (with luck, it will just be a jogger, and you can relax again).


 


As soon as the brain decides that everything is all clear, the hormones stop flowing, and the body can return to normal. At least that's the plan. In reality, many people produce so many stress hormones for so long that they don't fully recover. Perhaps they have a chronic infection, an anxiety disorder or some other condition that constantly puts the brain on full alert. Perhaps they live in a war zone or have a high-pressure job that keeps them on edge or financial troubles that just won't go away. Or they may simply have a tendency to overreact to small annoyances or worry about things they can't control.


 


Whatever the root cause, an oversupply of stress hormones can seriously threaten a person's health. In fact, stress-related diseases have become a hallmark of modern society. As Stanford stress researcher Robert Sapolsky wrote in his popular book, Why Zebras Don't Get Ulcers, "Stress-related disease emerges, predominantly, out of the fact that we so often activate a physiological system that has evolved for responding to acute physical emergencies, but we turn it on for months on end, worrying about mortgages, relationships and promotions."


 


The great irony is that stress-related diseases have become especially burdensome at a time when life itself is relatively easy, Sapolsky said in a phone interview. In the United States, at least, we live in a world of convenience and we don't have to fear polio, cholera or other catastrophic diseases that plagued our ancestors. Yet "there's no doubt that these are stressful times," he says. "We live well enough and long enough that we have the luxury of paying the price for stress."


 


Here's an overview of what can go wrong when stress takes over the body. Each of these threats gives all of us one more reason to manage the stress in our lives:


 


·         Cardiovascular disease: If you ever need to fight off an attacker or win a foot race, you'll be grateful that your heart beats faster in moments of stress. But if you're constantly worrying about your job or your marriage, your heart can suffer. Stressed-out people are prime targets for heart attacks and stroke, largely because long-term stress can raise blood pressure and strain the heart. In times of stress, the blood also becomes "stickier," potentially setting the stage for artery-clogging clots. Put together, these effects can have tragic consequences. In September 2004, Canadian researchers published a landmark study of nearly 25,000 people from 52 countries that identified the major causes of heart disease. The study found that lingering stress more than doubled the risk of heart attacks, putting it nearly on a par with smoking.


·         Weakened immune system: The immune system is very attuned to stress. While some germ-fighting cells, including those near the skin, become more active in stressful times, others shut down. Over time, this effect can leave gaping holes in the body's defenses. As a recent report from the National Institutes of Health puts it, "the immune cells are being bathed in molecules which are essentially telling them to stop fighting." As a result, people under stress whether they're studying for exams or going through a divorce are especially vulnerable to colds, flu and other infections. Stress may be particularly dangerous for people whose immune systems have already been weakened by advancing age or certain diseases. For example, studies suggest that stress can speed the progression from HIV infection to AIDS.


·         Gastrointestinal distress: Some people get butterflies in their stomachs, while others feel their stomachs get tied up in knots. However you describe it, there's no doubt that your digestive system responds strongly to stress. The brain maintains constant communication with the intestines and stomach through a network of nerves. When the brain is distressed, the digestive system is bound to notice. Lingering stress can irritate the intestines, causing cramping, diarrhea and constipation. If the stress persists, the intestinal distress can become a chronic problem known as irritable bowel syndrome. Contrary to common belief, stress doesn't cause stomach ulcers, at least not directly. But since stress weakens the immune system, it may make people more vulnerable to the infectious bacteria that do cause ulcers. A recent study found that people with generalized anxiety disorder, a condition that causes a near-constant state of worry, had more than their fair share of stomach ulcers. Stress doesn't cause inflammatory bowel disease, either, but it can definitely trigger flare-ups and make the symptoms worse, according to researchers.


·         Depression: The brain shifts its priorities under chronic stress. It may no longer be concerned with keeping you happy and healthy it merely wants to keep you alive, until the threat passes. "Frivolous" things like food, sex and fun suddenly seem much less important than they did before. Stressed-out people may not have the energy or desire to do the things that once gave them pleasure. From there, it can be a short trip to full-blown depression. A study published in Science magazine in 2003 found that genes play a major role in determining whether or not an overly stressed person will go on to develop depression.


·         Memory loss: A stressed-out brain may not be particularly committed to storing memories, either. Stress can undoubtedly hamper memory, as anyone who has ever tried to describe a car accident or a bank robbery can attest. In more scientific settings, people who are under stress tend to score poorly in verbal recall tests. Interestingly, people who simply take the stress hormone cortisol in pill form don't score very well, either. Severe stress, such as warfare or sexual abuse, can actually shrink the part of the brain that processes memories. There's also some research that suggests people who worry constantly may be more vulnerable to developing Alzheimer's disease.


·         Increased pain: Stress puts extra tension on muscles. Over time, this tension can lead to backaches and headaches. If you already have a painful condition such as arthritis, stress can magnify your pain. Since pain itself can cause stress, many people end up in a vicious cycle. The best way to break this cycle is to take control over stress.


 


You can't hope to banish stress from your life. You wouldn't even want to. As Sapolsky says, "If you took some sort of 'cortisol-be-gone' pill and you suddenly needed to catch the bus, you'd be in trouble. The much better approach is to figure out a way to engineer your life [to manage your stress]."


 


For starters, you can seek support from people around you, find a stress-releasing activity like walking or swimming, get regular exercise and try not to worry about things beyond your control. Your mind and body will get a much-deserved break, and your health is bound to improve. And when the next truly stressful situation arises, you'll be ready to respond. Alarms are much more effective when they only go off at the right times.


 

Chris Woolston, MS, is a health and medical writer with a master's degree in biology. He is a contributing editor at Consumer Health Interactive and was the staff writer at Hippocrates, a magazine for physicians. He has also covered science issues for Time, Inc. Health, WebMD and the Chronicle of Higher Education. His reporting on occupational health earned him an award from the Northern California Society of Professional Journalists.