Bruises hurt because broken blood vessels leak blood into the tissues under the skin, causing inflammation and pressure on nerve endings.
Here's a breakdown of the process:
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Blood Vessel Damage: A direct impact or force causes small blood vessels (capillaries) under the skin to rupture.
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Blood Leakage: Blood leaks out of these damaged vessels and into the surrounding soft tissues.
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Inflammation and Pressure: The leaked blood irritates the tissues. This irritation leads to inflammation (swelling), which puts pressure on nerve endings in the area.
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Nerve Stimulation: These nerve endings send pain signals to the brain, resulting in the sensation of pain associated with a bruise. The larger the bruise, the more blood is leaked, and the more pressure is exerted on the nerves, leading to more intense pain.
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Additional factors contributing to pain: The location of the bruise also plays a role in how much it hurts. Areas with more nerve endings (like shins or fingers) will generally be more painful than areas with fewer nerves or more cushioning.
Therefore, the pain associated with a bruise is a direct result of blood leaking into the surrounding tissues, causing inflammation and pressure on nerve endings, which then transmit pain signals to the brain.
