Blood in the Urine Without Pain: Could It Be Bladder Cancer?

Dernière mise à jour : 15 août 2026

• WordPress
• LinkedIn
• Courrier

Bladder cancer is the commonest cancer of the urinary tract, and it announces itself in a very particular way: blood in the urine, without any pain at all. That absence of pain is exactly what makes it dangerous, because pain is what usually sends people to a doctor.

One point before anything else, because it is the reason diagnoses get delayed. The bleeding is usually intermittent. It appears for a day or two, then stops completely, and the urine looks entirely normal again. That is not the problem resolving — the tumour does not go away when the bleeding does. A single episode of painless blood in the urine deserves investigation, even if it never comes back. Waiting to see whether it happens again is the most common and most costly mistake with this disease.

The two major facteurs de risque

1. Smoking

Tobacco is by far the largest risk factor: roughly 50% of bladder cancer patients have smoked, and smokers carry up to six times the risk of non-smokers. The risk rises with both how long and how heavily you smoked.

Two things are worth knowing about that. First, the elevated risk persists for decades after quitting — which means a man who stopped fifteen years ago should still take painless hematuria seriously rather than assuming smoking is behind him. Second, quitting is still worth it: the risk falls over time, and it also lowers the chance of a tumour coming back after treatment. The risk from electronic cigarettes is not yet established.

2. Occupational exposure

10–20% of cases are attributed to work exposure — chemicals used in making dyes, paint, rubber and petroleum products, inhaled over years. This is a modifiable risk: proper industrial safety practice and protective equipment genuinely reduce it. If your work has involved these, it is worth mentioning to your doctor, since it changes how seriously a single episode of hematuria should be taken.

What the assessment involves

The purpose of the workup is to find or exclude a tumour, and to distinguish it from the other things that cause blood in the urine — infection and stones being the commonest.

A full history and examination come first, then urine tests, then CT with contrast to image the whole urinary tract. The decisive investigation is cystoscopy — passing a telescope into the bladder to look directly at the lining. Nothing else sees the inside of the bladder as reliably, and the same procedure allows a suspicious area to be biopsied and a tumour resected, so it is diagnostic and therapeutic at once.

The encouraging part is that bladder cancer found early is very treatable. Most cases are non-muscle-invasive at diagnosis and are managed endoscopically, without removing the bladder. What decides the outcome, more than almost anything else, is how quickly the first episode of bleeding is investigated. If a tumour is found and treated, regular surveillance afterwards becomes part of the picture too.

Si vous avez eu du sang indolore dans les urines ou si vous souhaitez une évaluation du cancer de la vessie, le Dr Soarawee Weerasopone propose des consultations spécialisées au siège de l'hôpital de Bangkok. Prendre rendez-vous. Les rendez-vous à l'hôpital Samitivej Sriracha peuvent être pris en appelant le service d'urologie au 088-022-1445.

Foire aux questions sur le cancer de la vessie

Avis de non-responsabilité : This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. No medical advice, diagnosis or prescription is provided through personal messaging channels. Always consult a qualified healthcare professional before starting any medical treatment.