How stress affects the body: physiology, symptoms and long-term effects

What is stress and why do we feel it?

Stress is the body's natural reaction to any event that it perceives as a threat or challenge. It can be both physical exertion and psychological shock: work deadlines, relationship problems, illness, or even positive events that change the usual rhythm of life. In moderation, stress can be beneficial - it mobilizes strength, improves concentration. But when it is prolonged or repeated, it becomes dangerous to health.

How does stress affect the body?

When you experience stress, your body activates the hypothalamic-pituitary-adrenal axis (HPA), which stimulates the release of stress hormones—primarily cortisol and adrenaline. This leads to:

• increased heartbeat

• increased blood pressure

• muscle tension

• increased blood sugar levels

• immune system suppression

This is all fine in the short term. But with chronic stress, these processes wear down the body and cause problems with the heart, metabolism, sleep, and mood.

What symptoms indicate the effects of stress?

Physical symptoms:

• headache

• abdominal pain or indigestion

• rapid heartbeat

• increased sweating

• sleep disturbances (insomnia or excessive sleepiness)

• muscle tension, especially in the neck, shoulders, and back

Emotional symptoms:

• anxiety, irritability

• feeling overwhelmed

• frequent mood swings

• decreased motivation

• difficulty concentrating

Behavioral manifestations:

• overeating or, conversely, lack of appetite

• drinking alcohol or smoking to "calm down"«

• avoiding social interaction

• procrastination, putting off important matters

How does stress affect immunity?

In the short term, stress can even activate the immune system. But with prolonged exposure, cortisol levels remain constantly high — and this suppresses the production of white blood cells, reducing the body's ability to fight viruses and bacteria. Therefore, people who are often nervous or live in a state of constant anxiety get sick more often, recover more slowly, and may have exacerbations of chronic diseases.

Can stress cause chronic diseases?

Yes. According to Mayo Clinic, chronic stress is associated with the development of hypertension, coronary heart disease, type 2 diabetes, obesity, insomnia, and depression. All of these are not immediate consequences, but the result of long-term effects on hormonal and metabolic changes in the body. Stress can also affect hormonal balance and disrupt the functioning of the thyroid gland.

How to cope with stress?

• Regular physical activity – even 30 minutes of walking reduces cortisol levels

• Stable sleep pattern: go to bed and wake up at the same time

• A complete diet with enough protein, vitamins and omega-3 fats

• Meditation, breathing exercises, yoga

• Communicating with people you trust

• Working with a psychotherapist if it is difficult to cope on your own

Sources

1. Mayo Clinic – Stress management

2. WHO – Mental health and stress

3. American Psychological Association – Stress effects on the body

Author: Ulyana Anatolyivna Dzyuba

Director of Medi Lab Plus LLC, a doctor of the highest category. Has over 45 years of practical experience in medicine and laboratory diagnostics. Founder and head of the laboratory since 2007. More details…