What Does Stress Do to the Body?

Feeling stressed? You’re not the only one. According to a recent study, about 25% of Americans say they’re dealing with high levels of stress and another 50% say their stress is moderate.

These numbers may not surprise you since we all deal with work, family, and relationship stressors. But, what you may not know is that stress isn’t always a bad thing. In some cases, like when you’re starting a new job or planning a big event like a wedding, stress can help you focus, motivate you to do well, and even improve your performance.

But some of the reasons stress can be positive in these situations is that it’s short-term and it’s helping you get through a challenge you know you can handle.

Experiencing stress over the long-term, however, can take a real physical and mental toll on your health. Research has shown a connection between stress and chronic problems like high blood pressure, obesity, depression, and more.

Fight-or-flight

Stress can serve an important purpose and can even help you survive. For our ancestors, stress was a helpful motivator for survival, allowing them to avoid real physical threats. That’s because it makes your body think it’s in danger, and triggers that “fight-or-flight” survival mode.

Fight-or-flight mode refers to all the chemical changes that go on in your body to get it ready for physical action. In some cases, these changes can also make you freeze.

While this stress response can still help us survive dangerous situations, it’s not always an accurate response and it’s usually caused by something that’s not actually life-threatening. That’s because our brains can’t differentiate between something that’s a real threat and something that’s a perceived threat.

Stress in the Brain

When you encounter a stressor -- whether it’s an angry bear or an unreasonable deadline -- a chain of events kicks off in your brain. First, the amygdala, an area of your brain that processes emotion, gets information about the stressor through your senses. If it interprets that information as something threatening or dangerous, it sends a signal to your brain’s command center, known as the hypothalamus.

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The hypothalamus connects to the rest of your body through the autonomic nervous system. This controls automatic functions like your heartbeat and breathing through two different systems: the sympathetic and the parasympathetic.

The sympathetic nervous system triggers the fight-or-flight response, giving you the energy you need to respond to a threat. The parasympathetic does the opposite; it allows your body to go into “rest and digest” mode so that you can feel calm when things are safe.

When your hypothalamus gets a signal from your amygdala that you’re in danger, it sends signals to the adrenal glands and activates your sympathetic nervous system. The adrenals pump out adrenaline, causing your heart to beat faster, forcing more blood into your muscles and organs.

Your breathing might also quicken, and your senses might get sharper. Your body will also release sugar into your bloodstream, sending energy to all different parts.

Next, the hypothalamus activates a network called the HPA axis, which is made up of the hypothalamus, pituitary, and adrenals. This can cause these areas to release more stress hormones, including cortisol, which forces your body to stay wired and alert.

Stress on the Body

All of these chemical changes have short- and long-term effects on almost every system in your body:

  • Musculoskeletal system
    • Short term: Your muscles tense up suddenly and then release when the stressor is gone.
    • Long term: If your muscles are always tense, you can develop problems like tension headaches and migraines, as well as other chronic pains.

 

  • Respiratory system
    • Short term: You breathe harder and faster, and can even hyperventilate, which can cause panic attacks in some people.
    • Long term: If you have asthma or emphysema, breathing hard can make it difficult to get enough oxygen.

 

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  • Endocrine system
    • Short term: Stress hormones like adrenaline and cortisol give your body energy to either fight or run away from a stressor. Your liver also produces more blood sugar to give your body energy.
    • Long term: Some people don’t reabsorb the extra blood sugar that their liver pumps out, and they may be more likely to develop type 2 diabetes. Overexposure to cortisol can lead to thyroid problems and affect your ability to think clearly. It can also cause excess abdominal fat.

In men, chronic stress can also affect sperm and testosterone production, and cause erectile dysfunction and infections in the testes, prostate, or urethra. In women, chronic stress can worsen PMS, cause changes in the menstrual cycle, and missed periods. It can also aggravate symptoms of menopause and decrease sexual desire.

 

  • Gastrointestinal system
    • Short term: You may feel butterflies in your stomach, pain, or nausea, or might even vomit. Your appetite can change and you can have diarrhea, constipation, or heartburn.
    • Long term: Stress can lead to severe chronic pain and changes in your eating habits. You can also develop acid reflux.
Artículo médico de WebMD Reviewed by Joseph Goldberg, MD on November 03, 2016

Sources

SOURCES: 

Harvard Medical School: “Understanding the stress response.”

Gulf Bend Center: “Types of Stressors (Eustress vs. Distress).”

Stress Management Society: “What is Stress?”

University of Texas Counseling and Mental Health Center: “Fight or Flight.”

APA: “Stress Effects on the Body.”

Dartmouth Undergraduate Journal of Science: “The Physiology of Stress: Cortisol and the Hypothalamic-Pituitary-Adrenal Axis.”

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