Your kidneys are the unsung heroes of the body. Best known for removing waste and excess fluid, they also perform a variety of other essential roles: They regulate salt, potassium, and acid levels; keep blood pressure in check; produce vitamin D (to keep your bones strong); and control the production of red blood cells. And while kidney disease might not be high on your list of things to worry about, the truth is that over 20 million Americans have it, but many don't know it.
MORE: 5 Signs You're Not Getting Enough Vitamin D
"Symptoms of kidney damage are typically very subtle, and by the time you notice them, there is usually already serious harm done," says Jeremy Allen, DO, a board-certified family practitioner with American Family Care. "It is possible to lose as much as 90% of kidney function without having any overt symptoms."
The best way to protect yourself is to keep your blood sugar and blood pressure under control. "Hypertension and diabetes are the main culprits responsible for at least two-thirds of renal failure," says Jonathan Shaffer, MD, an internist affiliated with Concierge Choice Physicians. You should also see your doctor for an annual checkup, including a full blood workup. If levels of a molecule called creatinine are too high, additional blood tests, urine tests, and/or scans of your kidneys might be in order. (Heal your whole body with Rodale's 12-day liver detox for total body health.)
An annual exam is also a good time to review any meds you might be taking regularly. "If you have to take medications that are toxic to the kidneys, like some NSAIDs, certain antibiotics, or lithium or iodine-containing medications, talk with your doctor about other treatments," says Allen.
That said, don't wait for your yearly appointment if you notice any red flags. While kidney disease is often silent, there are some warning signs that should prompt you to hightail it to your doc's office.
Swelling and weight gain from fluid buildup (edema)
Your kidneys are supposed to eliminate waste from the body in the form of urine. "If the kidneys slow down or do not work well, then fluid can be retained. This can result in persistent swelling in tissue," says Mateo Ledezma, MD, a nephrologist with Kaiser Permanente Los Angeles Medical Center.
Urinating less than normal
More fluid being stuck in your tissues translates to less of it being flushed out of your body (and down the toilet). (Here's what the color of your pee says about your health.)
Feeling very tired or sleepy
"Part of the function of the kidneys is to help regulate a person's hemoglobin level," says Ledezma. When that process goes awry, you can end up anemic, which may cause your energy levels to plummet. (Feeling tired all the time? These 7 reasons might be the cause of your fatigue.)
Losing your appetite, feeling nauseated, or having trouble thinking clearly
These problems can occur when waste builds up in your system and starts to mess with other parts of your body, including your stomach and your brain.
Rising blood pressure
It's a bad cycle: Once the kidneys are damaged, they can't effectively control blood pressure. The force of blood pounding against the vessels stretches them—which causes further damage by scarring and weakening the blood vessels in the kidneys.
Having palpitations
"If your kidney damage is causing a buildup of potassium, you might notice an abnormal heartbeat," says Allen.
Watch Next
Mediterranean Diet Lowers Hypertension Risk
Salt Substitutes Reduce High Blood Pressure Risk
Should You Take BP While Lying Down?
COVID-19 May Trigger New-Onset High Blood Pressure
