Normal Levels. Blood sodium levels are measured in terms of millequivalents per liter or (mEq/L). The normal range for blood sodium is 135 to 145 mEq/L, according to Medline Plus. physician will often begin to monitor blood sodium levels when they drop lower than the 120 mEq/L range. While some adults can function sufficiently at these levels, many may have symptoms such as fatigue, lethargy, confusion, muscle cramps and nausea.
Rating Newest Oldest. Best Answer: The brain produces Endorphins to ease/relieve pain. The brain also produces seratonin, dopamine, melatonin, and others. Adrenaline is produced by the adrenal glands which rest on top the kidneys.
When pain or other sources of stress become significant and threatening, groups of cells in the brain release chemicals called endogenous opioid chemicals, commonly known as endorphins or enkephalins.