为什么眼泪是咸的

Tears come from lacrimal glands situated just over your eyeballs, and they contain water, mucus, fatty oils, and more than 1,500 proteins, per Healthline. The salty flavor in tears comes from the electrolytes in the water, which contain salt ions. This fluid is necessary to keep your eyes healthy. Mucus helps lubricate the eyes, and oil in tears keeps tears from evaporating. Mucus and oil are necessary to prevent dry eyes (via Verywell Health).

泪液来自眼球上方的泪腺，它们含有水、粘液、脂肪油和超过1500种蛋白质。眼泪中的咸味来自水中含有盐离子的电解质。这种液体是保持眼睛健康所必需的。粘液有助于润滑眼睛，眼泪中的油可以防止眼泪蒸发。粘液和油是预防干眼症所必需的。

Emotional tears also contain more stress hormones, according to biochemist Dr. William Frey. Frey told Psychology Today that when the body releases these hormones, it helps relieve stress. In addition, emotional crying may stimulate endorphins, which are the body's natural pain killers. While some people may think that crying makes them look weak, researchers suggest that doing so can relieve negative emotions while holding them back might lead to more mental distress, according to Healthline.

生物化学家威廉·弗雷博士说，情绪化的眼泪也含有更多的应激激素。弗雷告诉《今日心理学》，当身体释放这些激素时，有助于缓解压力。此外，情绪化的哭泣可能会刺激内啡肽，内啡肽是人体的天然止痛药。据Healthline报道，虽然有些人可能认为哭泣会让他们看起来很虚弱，但研究人员认为这样做可以缓解负面情绪，而抑制负面情绪可能会导致更多的精神痛苦。