According to Medical Xpress, stress can be more harmful than most people think. According to the authors, stress in early life can condition the human body to over-produce the stress hormone, cortisol. Overproduction of this hormone can lead to chronic conditions such as asthma, arthritis, diabetes, autoimmune diseases and even cancer.

Key Takeaways:

• The molecular mechanisms underlying the negative effects of early exposure to stress are unknown.
• In a paper recently published in Biology Open, they reported that zebrafish embryos that are chronically exposed to the stress hormone cortisol for just the first few days of life develop into adults with abnormal immune systems and signs of chronic inflammation.
• Coffman believes the aberrant immune gene regulation that his team observed in the adults derived from cortisol-treated embryos is due to glucocorticoid-induced developmental programming.

"Scientists have long known that chronic exposure to psychosocial stress early in life can lead to an increased vulnerability later in life to diseases linked to immune dysfunction and chronic inflammation, including arthritis, asthma, cancer, diabetes, heart disease and even mental illness."

http://medicalxpress.com/news/2016-10-role-early-life-stress-adult-illness.html