The short answer is yes, anxiety can make you physically sick. Too much anxiety can lead to symptoms of physical illness, worsen existing illness, or pre-dispose you toward illness. Our thoughts, emotions, perceptions, and behaviors all interact with and impact our physical function, and vice versa. The impact of uncontrolled anxiety can threaten your health over time. This is one reason why anxiety must be managed, ideally through a combination of psychotherapy, medication, and lifestyle changes. 

Understanding how anxiety effects your body 

Anxiety can manifest as a panic attack. A panic attack is a sudden shove into the Fight/Flight/Freeze (F3) mode, or sympathetic arousal. 

When we are faced with a threat to our survival, such as a dump truck locking up the brakes six feet away as we cross the street, our Sympathetic branch of our nervous system will activate and put us into F3. The response most conducive to our survival will be to get out of the way, or flee. To facilitate this, we will experience an adrenaline dump. 

The adrenal glands sit atop our kidneys. They will release the hormone adrenaline, which will:

• Dilate our pupils, to admit maximum light to our retinas, so we can see the threat.
• Increase heart rate and blood pressure to get more blood to our muscles.
• Increase the strength of muscle contractions, allowing us to leap out of the way
• Constrict small blood close to the outside of our body, turning us pale, which can control blood loss if we are lacerated.
• Slam our digestive processes to a halt, as they are not a priority in an emergency. We may experience this as a knot in the stomach.

This is the F3 response, which gives us the ability to withdraw from a threat, engage a threat, or lock up and be unable to move (Seltzer, 2015). 

Depending on the circumstances, any one of these responses can be conducive to our survival. 

Once the threat has been escaped, defeated, or left, the F3 response is reversed through the action of the Parasympathetic nervous system. 

This has been called the Rest and Digest (R & D) response. Our muscles relax, and heart rate and blood pressure goes down. Our pupils return to the normal size for the amount of ambient light, and our digestion resumes. This interaction between the Sympathetic and Parasympathetic systems maintains a sense of internal equilibrium in our bodies.

Chronic Anxiety & Physical sickness 

Here is the problem with anxiety:

Imagine being in that almost- hit- by- a- dump -truck feeling all the time.

It is too much. It is overwhelming. Instead of in balance, we are off-balance.

Chronic lower grade anxiety can wear you down. By the end of the day, you feel exhausted and achy. This is due to muscle tension, and your body working harder than it needs to all day. Anxiety can prevent you from sleeping well, so you don't feel rested the next day, and the cycle gets worse.

• With chronic anxiety, your body is releasing too much adrenaline, and other stress hormones, such as cortisol (Society for Endocrinology, 2019). and other glucocorticoids ( Ranibeer & Reetu, 2011). These hormones keep your body running in a state of emergency, or low-grade F3, making it difficult to relax and recover. This can cause long term effects on the health of your cardiovascular, digestive, and immune systems.

• Anxiety can impact your immune system (American Psychological Association, 2020) , resulting in more frequent upper respiratory infections, such as colds and flu. Over time, it may weaken your immune response to the degree that you become more vulnerable to cancer (Saplakoglu, 2019).

• Anxiety can also lead to or worsen hypertension (Medical News Today, 2020), or chronic high blood pressure.

• Anxiety is implicated as a trigger or exacerbating factor in migraine headaches, (American Migraine Foundation, 2020) tension headache, indigestion, and acid reflux (Choi, et al, 2018).

• Anxiety can lead to erectile dysfunction (Hedon, 2003) in men, and sexual problems in women (Medical News today, 2020a).

Conclusion 

Anxiety is an emotion. It must be available in the correct amounts for us to function well. 

There are individual differences in how much anxiety one experiences. 

Too little anxiety can lead to reckless behavior or a lack of urgency about accomplishing a task. A degree of anxiety motivates you to wear a seat-belt, look both ways when crossing the street, and to delay gratification to get work done. 

Too much anxiety can make us sick. We need to be in the Goldilocks Zone – not too much, not too little, but just right- for anxiety to serve us well, instead of making us sick.

References

American Migraine Foundation. (2020). The Link Between Migraine, Depression and Anxiety. Retrieved March 28, 2020 from https://americanmigrainefoundation.org/resource-library/link-between-migraine-depression-anxiety/

American Psychological Association. (2020). Stress Weakens the Immune System. Retrieved March 28, 2020 from https://www.apa.org/research/action/immune

Choi, J.M. et al . (2018) Association Between Anxiety and Depression and Gastroesophageal Reflux Disease: Results From a Large Cross-sectional Study. Journal of Neurogastroenterolgy and Motility. 24(4): 593–602.doi: 10.5056/jnm18069.

Hedon, F. (2003).Anxiety and erectile dysfunction: a global approach to ED enhances results and quality of life. International Journal of Impotence. Res 15, S16–S19. https://doi.org/10.1038/sj.ijir.3900994

Medical News today. (2020). Can anxiety cause high blood pressure?. Medical News Today. Retrieved March 28, 2020 from https://www.medicalnewstoday.com/articles/327212#anxiety-causing-high-blood-pressure

Medical News today. (2020a). What you need to know about vaginismus . Medical News Today. Retrieved March 28, 2020 from https://www.medicalnewstoday.com/articles/175261

Ranibeer S, and Retu, K. (2011). Stress and hormones. Indian Journal of Endocrinology and Metabolism. 15(1): 18–22. doi: 10.4103/2230-8210.77573.

Saplakoglu, Y. (2019). Can Chronic Stress Cause or Worsen Cancer? Here's What the Evidence Shows. Live Science. Retrieved March 28, 2020 from https://www.livescience.com/65342-chronic-stress-cancer.html

Seltzer, L. (2015). Trauma and the Freeze Response: Good, Bad, or Both? Psychology Today. Retrieved March 28, 2020 from https://www.psychologytoday.com/us/blog/evolution-the-self/201507/trauma-and-the-freeze-response-good-bad-or-both

Society for Endocrinology. (2019). You and your Hormones: Cortisol. Society for Endocrinology. Retrieved March 28, 2020 from https://www.yourhormones.info/hormones/cortisol/