Did you know that kid­neys, like the heart and brain, are es­sen­tial or­gans? March 13th, 2025 is World Kid­ney Day. Chron­ic kid­ney dis­ease is a pro­gres­sive con­di­tion af­fect­ing more than 10 per cent of peo­ple world­wide, or about 800 mil­lion in­di­vid­u­als. This dis­ease al­ready threat­ens even more than 10 per cent, and the threat will on­ly grow. Why? In short, be­cause of cli­mate change and the dam­age it can cause even to healthy kid­neys.

To raise aware­ness about the im­por­tance of main­tain­ing healthy kid­neys, the in­ter­na­tion­al com­mu­ni­ty com­mem­o­rates World Kid­ney Day.

Kid­ney health and heat

Know­ing whether you have healthy kid­neys is of­ten dif­fi­cult, be­cause many with kid­ney dis­ease have no symp­toms. The kid­ney is a vi­tal or­gan, fil­ter­ing waste prod­ucts, tox­ins and chem­i­cals from your blood, and get­ting rid of them in the urine. Keep­ing your kid­neys healthy is cru­cial for your health. While some are sim­ply more prone to de­vel­op­ing kid­ney prob­lems, we are all now more sus­cep­ti­ble. Why is this?

Plan­e­tary tem­per­a­tures have in­creased by al­most 2°C, caus­ing in­creased fre­quen­cy of ex­treme heat, more marked near the equa­tor, the ge­o­graph­i­cal lo­ca­tion of T&T and the Caribbean. The body’s re­sponse to high tem­per­a­tures is sweat­ing, which cools the body. Ex­ces­sive sweat­ing, how­ev­er, leads to de­hy­dra­tion, re­duc­ing blood flow to the kid­neys. An­oth­er kid­ney-threat­en­ing fac­tor is the 80-90% hu­mid­i­ty the re­gion of­ten ex­pe­ri­ences. These two marks of cli­mate change mean that the Heat In­dex for T&T (cal­cu­lat­ed us­ing both tem­per­a­ture and hu­mid­i­ty) is com­mon­ly in the Red Zone. A high heat in­dex re­sults in pro­fuse sweat­ing, de­hy­dra­tion and can re­sult in de­te­ri­o­ra­tion of kid­ney func­tion. Some suf­fer­ing these ef­fects may be di­ag­nosed with ARF (Acute Re­nal Fail­ure), which can be re­versed through re­hy­dra­tion and re­plac­ing elec­trolyte loss. Co­conut wa­ter, rich in potas­si­um, and oth­er prod­ucts are avail­able for re­hy­dra­tion, though one should be cau­tious pur­chas­ing en­er­gy drinks which may con­tain caf­feine or re­lat­ed prod­ucts.

Who is vul­ner­a­ble?

If un­treat­ed, ARF can progress to CRF, Chron­ic Re­nal Fail­ure. You’re prob­a­bly won­der­ing who is most sus­cep­ti­ble. Un­der­ly­ing health con­di­tions like high blood pres­sure, di­a­betes, heart dis­ease, obe­si­ty, sick­le-cell dis­ease, pre-ex­ist­ing re­nal dis­ease, tak­ing cer­tain med­ica­tions like di­uret­ics (make you uri­nate more), some an­ti­hy­per­ten­sives (blood pres­sure re­duc­ers) and non-steroidal an­ti-in­flam­ma­to­ry drugs put you at risk. Be­cause the body func­tions less well, such in­di­vid­u­als are more prone to heat stress and heat stroke, which can lead to kid­ney in­jury.

One doc­tor re­cent­ly shared that her el­der­ly pa­tients are of­ten un­able to care for them­selves dur­ing very hot pe­ri­ods, be­cause of flu­id and elec­trolyte loss. In­fants and young chil­dren who have a high­er sur­face area-to-body mass ra­tio, al­so ab­sorb heat from the en­vi­ron­ment more eas­i­ly and are at high­er risk.

Out­door work­ers, in­clud­ing the mil­i­tary, po­lice, agri­cul­tur­al work­ers, those in con­struc­tion and ath­letes are at high­er risk of kid­ney in­jury. Stren­u­ous ac­tiv­i­ty dur­ing the ex­treme­ly hot/hu­mid con­di­tions de­scribed wors­en out­comes. I have vivid mem­o­ries of pa­tients com­ing to me with dis­coloured urine and ex­treme­ly painful mus­cles, be­cause high heat gen­er­at­ed by in­creased mus­cle ac­tiv­i­ty dam­aged their mus­cle cells, re­leas­ing tox­ins in­to their blood­stream and dam­ag­ing their kid­neys. You may have just played mas and might be won­der­ing how to find out if your kid­neys are healthy!

How is kid­ney dis­ease di­ag­nosed?

Your doc­tor can do urine and blood tests con­firm­ing kid­ney health or prob­lems. For those with un­der­ly­ing dis­eases or his­to­ries of re­nal dis­ease, more de­tailed stud­ies like ul­tra­sounds, CT scans, MRIs or re­nal biop­sies can be done to find out if you have CRF. Peo­ple with CRF are put on re­stric­tive di­ets that in­clude low pro­tein and elec­trolytes. Such in­di­vid­u­als are can­di­dates for re­nal dial­y­sis and may ben­e­fit from a kid­ney trans­plant.

How to pro­tect my kid­neys?

What should you do if you want to main­tain healthy kid­ney func­tion? Don’t smoke, avoid con­sum­ing ex­ces­sive al­co­hol and caf­feine, main­tain ide­al body weight, ex­er­cise fre­quent­ly and prac­tice a healthy lifestyle. Treat un­der­ly­ing health con­di­tions and re­mem­ber: every­thing in mod­er­a­tion. Re­mem­ber to drink enough, avoid­ing sug­ary high-en­er­gy drinks (even when they’re ad­ver­tised to seem like the bet­ter choice!), opt for shady ar­eas, min­imise heat ex­po­sure, wear light cloth­ing, hats, sun­glass­es, sun­block and choose cool­er times for out­door ac­tiv­i­ties. Cold drinks, cool show­ers, air-con­di­tion­ing or vis­it­ing a near­by mall if you do not own a unit, are great op­tions. Keep an eye on me­dia up­dates about heat!

Con­clu­sion

Be aware of what keeps kid­neys healthy, treat un­der­ly­ing dis­eases, and stay cool and hy­drat­ed. Re­mem­ber, in­fants, chil­dren, the el­der­ly, out­door work­ers and peo­ple us­ing cer­tain med­ica­tions are at high­er risk. While avoid­ing heat is im­pos­si­ble in T&T and the wider Caribbean, us­ing every­thing you just learned and lis­ten­ing to me­dia up­dates about ex­ces­sive­ly hot days/days with high heat in­dices will go a long way to­wards pro­tect­ing your­self – and one of your body’s most vi­tal or­gans. Cli­mate change is ac­cel­er­at­ing, so stay in­formed, and stay safe.

Dr Paula Hen­ry, MB BS, MBA, MPH is a di­rec­tor of the Earth­Medic and Earth­Nurse Foun­da­tion for Plan­e­tary Health

phen­ry@earth­medic.com

The fore­go­ing was a week­ly col­umn by Earth­Medic and Earth­Nurse NGO to equip read­ers to face the cli­mate and health cri­sis.