Chronic kidney disease (CKD) affects more than 10% of the adult population and is one of the most silent but potentially serious conditions of the renal system. Care must be especially taken during summer, as heat, dehydration, and changes in routine can worsen patients’ conditions. “In the hot months, the risk of dehydration increases significantly, which can lead to acute deterioration of kidney function in individuals who already have compromised kidneys,” explains Dr Edduin Miguel Martín, head of the Nephrology Service at Hospital Quirónsalud Tenerife.
CKD is a progressive and irreversible alteration of kidney function. It is diagnosed when the glomerular filtration rate (GFR), which indicates how well the kidneys are functioning, falls below 60 ml/min for more than three months, or if there is persistent structural damage detectable through medical tests. “The main causes of chronic kidney disease,” details Dr Martín, “are poorly controlled diabetes mellitus, high blood pressure, autoimmune diseases, hereditary conditions like polycystic kidney disease, or chronic use of medications such as anti-inflammatories. It typically affects individuals over 60, diabetic patients, hypertensives, or those with cardiovascular issues.”
During the summer months, the rise in temperature leads to greater liquid loss through sweat. In the general population, this can be easily corrected by drinking water, but for renal patients, maintaining fluid and electrolyte balance is more delicate. “Mild dehydration in these patients can lead to cramps, drops in blood pressure, or even acute kidney injury, which in some cases can be irreversible,” warns the nephrologist from Hospital Quirónsalud Tenerife.
The specialist recommends avoiding going out during the hottest parts of the day, wearing light clothing, and maintaining proper hydration depending on the stage of the disease. “For individuals taking diuretics or antihypertensives, it is especially important to review their medication with their doctor, as heat can amplify their effects and lead to hypotension,” stresses Dr Martín.
Among the symptoms that should alert patients or their families are reduced urine output, extreme fatigue, swelling in legs or face, nausea, dizziness, or sudden changes in body weight. Regarding diet, Dr Martín reminds that “not all fluids are equal, nor are all fruits advised.” It is recommended to prioritise water over soft drinks or industrial juices, and to consume fruits such as apples, pears, or watermelon in controlled portions.
Moreover, it is crucial to limit the intake of ultra-processed foods, such as processed meats, ready-made meals, cola drinks, and industrial dressings, as they often contain high amounts of sodium, phosphorus, and hidden potassium, warns the specialist. While traditionally the consumption of fruits and vegetables has been restricted due to their potassium content, current recommendations advocate for individualised assessment, prioritising a heart-healthy diet based on fresh and natural foods.
Individuals undergoing haemodialysis or peritoneal dialysis require even stricter monitoring. They must adjust their fluid intake, even counting ice cubes or gelatins, not alter their dietary guidelines without consulting the specialist, and keep their dialysis session schedule, even when on holiday. “Under no circumstances should a dialysis session be cancelled for holiday reasons. There are resources to continue treatment at other centres, but skipping a session can jeopardise the patient’s life,” insists the nephrologist.
