Your friend may be onto something. While eating excess salt in everyday life can cause bloating, not having enough of it can cause swelling too. And it鈥檚 far more likely your sodium levels are on the low side after hiking all day.
It鈥檚 possible, if you don鈥檛 take in enough salt while you鈥檙e hiking but drink a lot of water, to dilute the sodium levels in your body to unsafe levels. When that happens, you have , and one of the symptoms is鈥攜ou guessed it鈥攑uffy hands, because the extra water in your system enters your cells and causes them to swell.聽 But should you OD on water and forget the salt, you鈥檒l likely experience other symptoms of hyponatremia as well, including 鈥渉eadaches that won鈥檛 go away, confusion that your friends recognize, but you might not, irritability, swollen feet and ankles,鈥 says Dr. Bob Murray, the founder of , and the former director of the Gatorade Sports Science Institute.
(How much water is too much? Everyone鈥檚 needs are different. At rest, the average set of kidneys can handle up to a liter of liquid per hour, according to . But while you鈥檙e exercising, that amount can fall drastically, because your body releases an anti-diuretic hormone that lowers the kidney鈥檚 excretion capacity.)
鈥淚f you get puffy hands, you don鈥檛 want to disregard it,鈥 Murray says. 鈥淏ut nine times out of 10, it鈥檚 just fluid pooling in the hands.鈥
And that鈥檚 the other, much simpler explanation for your Michelin Man hands: blood is pooling in them. This is usually not a big deal, and the problem should resolve within a few hours after your hike. But if your fluffy fingers are really bothering you, try lightening your load. The straps of your backpack can 鈥渇urther reduce return venous blood to the heart,鈥 Murray says, so it may help to cut down your pack鈥檚 weight. Murray also recommends holding your hands over your head periodically, stopping to pick things up, and making fists to help move the blood back toward the heart.
The Bottom Line
If you feel fine, your puffiness is likely due to the pooling of blood in your hands. But if you have any of the symptoms of hyponatraemia, your sausage fingers might be the sign of a serious electrolyte imbalance, indicating that you need to take in more salt.聽