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.
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.
When chopping an onion, the eyes can water and the nose run; this is precisely why the onion is useful as a healing poultice. Onion can improve circulation and helps break up congestion. The high sulfur content in onions causes thick mucus to move outward toward the skin.