1 Pain that does not diminish with rest, and pain that may be worse at night than during the day. 2  Back pain along with constitutional symptoms, such as loss of appetite, unplanned weight loss, nausea, vomiting, or fever, chills or shakes.
Unstable chemicals. Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. Scientists used to blame the enzyme allinase for the instability of substances in a cut onion.
Find out why you cry onions make you cry when you cut them. Learn about the chemistry involved and how you can keep it from happening. Find out why you cry onions make you cry when you cut them. Learn about the chemistry involved and how you can keep it from happening. Learn Why Onions Make You Cry