2025年08月15日 / ライフスタイル

"Writhing Pain": Surge in "Urolithiasis" During Scorching Summer - Be Cautious of Disrupted Eating Habits During Obon Homecoming

"Writhing Pain": Surge in "Urolithiasis" During Scorching Summer - Be Cautious of Disrupted Eating Habits During Obon Homecoming

1. What is Urolithiasis?

Urolithiasis is a condition where "stones (crystal aggregates)" form in the urinary tract from the kidneys to the bladder. When a stone blocks the ureter, it obstructs the flow of urine and causes intense pain. This pain is often described as "comparable to childbirth" or "agonizing," and many patients require emergency transport.

2. Why Does It Increase in Extreme Heat?

  • In summer, the body's water content rapidly decreases due to sweating.

  • Urine volume decreases, making urine more concentrated and calcium and uric acid more likely to crystallize.

  • Dehydration during outdoor activities and exercise doubles the risk of stones.


Data shows that on extremely hot days exceeding 35°C, the number of cases increases by 20-30% compared to usual.

3. Obon Homecoming and Stone Risk

During the Obon period, lifestyle rhythms and eating habits tend to become irregular due to homecoming and travel.


  • Consuming large amounts of foods high in purines such as grilled meat, fried foods, and fish roe.

  • Excessive alcohol consumption, such as beer.

  • Air conditioning indoors makes it hard to feel thirsty, leading to insufficient hydration.


When these factors overlap, the risk of stone formation increases sharply.

4. Characteristics of Symptoms

  • Sudden severe pain from the lower back to the lower abdomen.

  • Hematuria (often detectable through urine tests even if not visible).

  • May be accompanied by nausea or vomiting.

  • Pain can last from several hours to several days.

5. Medical Response

A CT scan is used to check the size and location of the stone. If natural expulsion is possible, painkillers are used for observation. For large stones or severe blockages, "Extracorporeal Shock Wave Lithotripsy (ESWL)" is used to break them down and promote expulsion.

6. High Recurrence Rate

Urolithiasis has a high recurrence rate, with about half of those who experience it once having another episode within five years. Improving lifestyle habits is essential.

7. Prevention Tips

  • Hydration: Aim for 2 liters a day, drinking frequently. Beverages like beer and green tea can have strong diuretic effects and may be counterproductive, so focus on water and barley tea.

  • Dietary Improvements:

    • Limit salt intake

    • Avoid excessive intake of animal protein

    • Adequate calcium intake (such as from dairy products) can actually have a preventive effect

  • Regular Lifestyle: Avoid overeating and drinking, and especially focus on hydration during summer.

8. Specific Examples to Watch Out for During Obon

  • Consuming large amounts of meat and beer at barbecues during homecoming → Increased stone risk

  • Holding urine during car travel → Urinary retention increases risk

  • Spending long hours in air-conditioned rooms and forgetting to drink water → Dehydration progresses

9. What to Do If You Get Urolithiasis

If sudden severe pain occurs, do not endure it and go to the emergency room. It is important to receive a diagnosis from a specialist rather than trying to manage with over-the-counter painkillers.

10. Summary

The combination of extreme heat and Obon dietary habits poses a "double risk" for urolithiasis.

  • Loss of water through sweat

  • Concentration of urine due to dietary disruption

  • Excessive alcohol and salt intake exacerbate the issue

To get through this summer, "drink plenty of water" and "avoid overeating and drinking" are key.




List of Reference Articles