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Chronic stress can affect your whole body — from your head to your heart.

Stress is a powerful thing. In small doses, it can motivate us to ace that presentation at work or land our dream job. But when left unchecked for a long time, stress is anything but motivating.

So, what's really going on when you're stressed? And how can paying attention to your stress improve your health?

What is stress?

Whether you’ve just narrowly avoided a car accident or are worried about losing your job, stressful situations trigger a release of hormones known as the “fight-or-flight response.”

The reaction starts in a part of your brain called the amygdala, which processes emotions like fear. When the amygdala senses danger, it sends a distress signal to your hypothalamus, which communicates to the rest of your body via the nervous system. When the hypothalamus gives the signal, your brain releases hormones like epinephrine (also called adrenaline) and the stress hormone cortisol into your bloodstream.

“The fight-or-flight response is a survival mechanism that lets us react quickly to dangerous situations by preparing to either fight or run from the stressor,” explains Laura Keys Campbell, PhD, chief of outpatient psychology and therapy at Geisinger Medical Center in Danville. 

Some physical signs your fight-or-flight response has kicked in include:

  • Rapid breathing and heart rate
  • Heightened senses and awareness
  • Tense muscles
  • Pale or flushed skin
  • Cold or clammy hands
  • Dilated pupils
  • Dizziness
  • Nausea

In a truly dangerous situation, this response can be lifesaving. But when stress is chronic and this system is activated too often, it takes a toll on your body.

How does stress affect the body?

Left unmanaged, stress impacts you physically, mentally and emotionally.

“Research shows that chronic stress can have effects on almost every system in the body — from the heart to the digestive system to the immune system,” Dr. Campbell says. 

Here are nine effects of stress on your body:

1. Elevated blood pressure

It’s normal for your blood pressure to temporarily spike when your fight-or-flight response is activated. But when stress becomes chronic, it could lead to long-term high blood pressure, which increases your risk of heart disease. 

2. Weakened immune system

Do you feel like you always catch a cold after finishing a stressful project? It’s probably because of cortisol's effect on your immune system.

“Cortisol temporarily inhibits your ability to fight off infections because it decreases your body’s supply of white blood cells,” explains Dr. Campbell. “This can make you more prone to catching illnesses like the cold or flu.”

3. Chronic inflammation

But too much cortisol over a long period can also cause your immune system to overreact in the form of inflammation. 

“Inflammation is a critical part of the healing process as your body responds to intruders like viruses and bacteria,” says Dr. Campbell. “But when no intruders are present and your body is still sending out inflammatory signals, it can lead to chronic inflammation.” 

Chronic inflammation has been linked to several health conditions including:

  • Arthritis
  • Diabetes
  • Heart disease
  • Crohn’s disease, ulcerative colitis and irritable bowel syndrome (IBS)
  • Alzheimer’s and dementia
  • Cancer

“Going through periods of high stress doesn’t automatically mean you’ll develop one of these conditions, but it can put you at increased risk — or make symptoms worse if you already have something like arthritis or IBS,” explains Dr. Campbell.

4. Headaches

Why does it always seem like a pounding headache strikes right when your frustration reaches its peak? 

“Because your muscles tense up during the fight-or-flight response, chronic stress can cause tension headaches or trigger migraines in people prone to them,” says Dr. Campbell.

5. Anxiety, depression or mood changes

Beyond the physical effects, stress can also have a big impact on your mental health. 

“Studies have shown that unmanaged stress can trigger anxiety, depression, fatigue, difficulty concentrating and irritability,” says Dr. Campbell. “It can also lead to unhealthy coping mechanisms like drug and alcohol abuse.”

6. Weight gain

There’s a reason why you reach for mac and cheese or cake whenever you’re stressed.

“Cortisol can cause cravings for foods rich in fat, sugar and salt. This is because our bodies are looking for quick doses of energy to prepare for whatever perceived threat we’re facing,” explains Dr. Campbell. 

Over time, reaching for these comfort foods during stressful situations could become an unhealthy habit leading to weight gain.

7. Difficulty sleeping

You’re too stressed to sleep, so you stay up late. But then you’re so tired that you feel even more stressed and stay up later the next night. Sound familiar?

“Stress and sleep can be a slippery slope,” says Dr. Campbell. “Increased adrenaline and cortisol can make you feel too on edge to fall asleep and sleep deprivation can make you more likely to get stressed out.” 

8. Decreased sex drive

Wondering where your libido went? First consider how stressed you’ve been. 

“When we’re going through periods of high stress, it’s perfectly normal for sex to be the last thing on our minds,” says Dr. Campbell. “This is typically only temporary and should resolve as you cope with the stress.”

9. Changes to your menstrual cycle

If you’ve noticed your period is late, heavier or shorter than usual, it could be stress. 

“Because of chronic stress' effect on hormones, it could cause irregular menstrual cycles,” explains Dr. Campbell. “You should always talk with your doctor about any changes in your period and be sure to mention if you’ve experienced any long-term stress lately.”

Ways to relieve stress

So, how do you reduce stress once you have it? 

“It might be tempting to overeat, drink alcohol or use tobacco, but those things provide temporary relief at best, and only add to health problems in the long run,” says Dr. Campbell. 

Some healthier ways to relieve stress include:

“Exercise is an especially great way to reduce or eliminate stress, boost your energy levels and improve your mood, not to mention your overall health,” Dr. Campbell notes. “And you don’t have to run miles to get the benefits for your mind and body. You can start small by taking a daily walk.”

Need more help or guidance?

If you’re having a hard time identifying what’s causing your stress or the effects aren’t going away, talk to your doctor. They can work with you to identify causes and discuss coping techniques. They might also refer you to a licensed therapist or a professional counselor who can help you pinpoint and possibly eliminate sources of stress.

And if constant stress leaves you with sudden chest pain and shortness of breath, get help immediately.

“Listen to your body,” Dr. Campbell says. “And when it tells you it’s under stress or you need help coping, pay attention to that message, so you can enjoy a long, healthy and high-quality life.”

Next steps: 

Learn about mental health care at Geisinger
Discover how to boost your happy hormones naturally
Explore ways to reduce stress as a caregiver