Stress is a maladaptive state of the body in which the sympathetic nervous system is overactivated, causing acute or chronic physical, psychological, and behavioral impairment. This overactivation of the sympathetic nervous system in order to maintain the state of stability or homeostasis is a response to the stimulus that wants to break the mental and physical balance and stability of the body.
In layman terms, there is a part of our nervous system – the Autonomic Nervous System (ANS). This is responsible for controlling the internal organs, including the blood vessels, stomach, intestine, liver, kidneys, bladder, genitals, lungs, pupils, sweat, salivary and digestive glands, and the most important organ – the HEART. The ANS has 2 parts – The sympathetic Nervous System (SNS) and the Parasympathetic Nervous System (PNS).
The PNS controls the body during ordinary situations. It conserves and restores the body, slows down the heart rate, decreases blood pressure, stimulates the digestive tract to process food, and eliminates waste. Energy from this processed food is used to restore and rebuild the tissues.
The SNS prepares the body for stressful and emergency situations, which is also called FIGHT or FLIGHT. It increases the heart rate, the force of heart contractions, widens the airways to make breathing easier, and causes the body to release stored energy. It also causes palms to sweat, pupils to dilate and hair to stand. It slows down processes that are less important in emergencies like urination and digestion.
Stress is a measure of this overactivation of the sympathetic nervous system in the resting phase.
What is the medical significance of HRV parameters?
Apart from quantifying the physical restoration and rebuilding of the body as mentioned above, there are numerous studies conducted worldwide by renowned cardiological societies, universities, and institutions that show a clear and significant relationship between HRV parameters and various risks associated with diseases ranging from blood pressure to mortality due to CVDs (CardioVascular Disorders). HRV parameters are a part of many medical scores used to find the risk level of a patient.
Moderate Stress Level
Low Stress Level
High Stress Level
Impact of perpetual high stress
Overactivation of the SNS for longer periods of time is harmful to the body and can lead serious physical disorders like pain or tension in your head, chest, stomach, or muscles, digestive problems, diarrhea and constipation, nausea and vomiting, reproductive issues, changes to your heart rate and blood pressure.
Long-term consequences of high stress
Mental health problems, such as depression, anxiety, and personality disorders
Cardiovascular disease, including heart disease, high blood pressure, abnormal heart rhythms, heart attacks, and stroke
Obesity and other eating disorders
Sexual dysfunction, such as impotence and premature ejaculation in men and loss of sexual desire in both men and women
Skin and hair problems, such as acne, psoriasis, and eczema, and permanent hair loss
Gastrointestinal problems, such as GERD, gastritis, ulcerative colitis, and irritable colon