Stress is part of your body’s normal reaction to a perceived threat. And it isn’t necessarily a bad thing. It can drive you to accomplishing things and help you avoid potentially dangerous situations.

But too much stress can have a big impact on your physical and emotional health, leading some experts to take a look at the possible role of stress in the development of cancer.

So, can stress cause cancer? The answer isn’t clear yet. Read on to learn about the common theories about the link between cancer and stress, the existing evidence, and how stress might affect existing cancer.

Before diving into the relationship between stress and cancer, it’s important to understand what stress involves and the different forms in can take.

When your brain recognizes something as a possible threat or danger, a combination of nerve and hormone signals are sent to your adrenal glands. In turn, these glands produce hormones, including adrenaline and cortisol, that kickstart the stress response.

Acute stress

Acute stress is what most people imagine when they talk about stress. It’s typically short-lived and triggered by specific situations.

These might include:

  • needing to slam on your brakes to avoid hitting a car that’s pulled in front of you
  • having an argument with a family member or friend
  • being in traffic that’s causing you to be late to work
  • feeling pressure to meet an important deadline

Acute stress can cause several physical symptoms, including:

  • rapid heart rate
  • increased blood pressure
  • quick breathing
  • muscle tension
  • increased sweating

These effects are usually temporary and resolve once the stressful situation is over.

Chronic stress

Chronic stress happens when your stress response is activated for prolonged periods of time. It can wear you down both physically and emotionally.

Examples of things that can lead to chronic stress include:

  • living in a dysfunctional or abusive home situation
  • working a job that you hate
  • having frequent financial trouble
  • living with a chronic illness or caring for a loved one who does

Compared to acute stress, chronic stress can have long-term effects on your physical and emotional health.

Over time, chronic stress can contribute to:

  • heart disease
  • digestive issues
  • anxiety and depression
  • weight gain
  • problems sleeping
  • difficulties concentrating or remembering things
  • fertility problems
  • weakened immune system

There are a lot of theories about how stress could possibly contribute to a person’s risk of developing cancer.

Here’s a look at some of the big ones:

  • Continuous activation of the stress response and exposure to the associated hormones could promote the growth and spread of tumors.
  • The immune system can be important for finding and eliminating cancer cells. But chronic stress can make it harder for your immune system to carry out these tasks.
  • Prolonged stress could lead to a state of inflammation that may contribute to cancer risk.
  • Stress can prompt people to turn to unhealthy coping mechanisms, such as smoking, drinking excessive amounts of alcohol, or overeating. All of these can increase your risk of developing cancer.

The relationship between stress and cancer is the source of many ongoing studies. Here’s a snapshot view of some relevant findings.

One 2013 review of 12 studies assessed work stress and how it relates to cancer risk. They found that work stress wasn’t associated with overall cancer risk. Further, work stress wasn’t linked with the development of specific cancers, such as those of the prostate, lung, and breast.

However, a more recent 2017 study investigated the past levels and duration of job stress experienced by more 2,000 men newly diagnosed with prostate cancer. It found that perceived workplace stress was associated with a higher risk of prostate cancer.

A large 2016 study of 106,000 women in the United Kingdom looked at whether frequent stress or negative life events affected their risk of breast cancer. In the end, the study didn’t find consistent evidence to suggest that frequent stress factors into someone’s breast cancer risk.

Overall, there still isn’t enough conclusive evidence to definitely say whether stress causes cancer or even increases someone’s risk.

indirect vs. direct causes

Even in cases where there does appear to be a link between stress and cancer, it’s still unclear whether stress contributes directly or indirectly.

For example:

  • Someone under chronic stress takes up smoking as a means of relief. Is it the stress or the smoking that increases their risk of cancer? Or is it both?
  • Someone experiences chronic stress for several years while caring for a family member with cancer. Down the line, they develop cancer themselves. Was stress a factor? Or was it genetics?

As experts begin to better understand both cancer and stress individually, we’ll likely learn more about how the two relate to each other, if at all.

While it’s unclear whether stress causes cancer, there is some evidence that stress can have an effect on existing cancer by speeding up tumor growth and metastasis. Metastasis occurs when cancer spreads from its initial location.

A 2016 study in a mouse model of pancreatic cancer exposed mice to chronic stress. The investigators found that after five weeks, the stressed mice had larger tumors and a reduced survival rate. Their immune systems were also significantly weakened.

A 2019 study examined human breast tumor cells implanted in mice. Researchers found an increase in the activity of receptors for stress hormones in sites were metastasis occurred. This suggests that the activation of these receptors by stress hormones could play a role in metastasis.

Regardless of whether stress causes cancer, there’s no doubt that stress affects your overall health.

Protect your physical and emotional well-being with these tips:

  • Set priorities and boundaries. Determine what needs to be done now and what can wait a little bit. Learn to turn down new tasks that may overextend or overwhelm you.
  • Take time to cultivate your relationships with loved ones.
  • Burn off steam keep your heart healthy with regular exercise.
  • Try out relaxation techniques such as yoga, deep breathing, or meditation.
  • Make sleep a priority. Aim for seven to eight hours per night.

If these tips aren’t cutting it, remember that most of us can use a little help from time to time. Don’t hesitate to reach out to a mental health professional if you’re feeling overwhelmed. Here are five affordable options to get you started.

Stress is a natural response that your body has to perceived threats. Stress can be acute or chronic. Having chronic stress can put you at risk for a variety of health conditions, such as heart disease and depression.

Whether or not chronic stress puts you at risk of developing or causes cancer is unclear. Some studies indicate that it does and others that it doesn’t. Stress may be just one of many factors contributing to the development of cancer.