CO₂ Bath: Carbon Dioxide Therapy and Gas Baths 2026

Key Facts

CO₂ Bath at a Glance

Feature	Details
Definition	Immersion in water naturally enriched with dissolved carbon dioxide gas
Key Spas	5: Mariánské Lázně, Poděbrady, Karlovy Vary, Teplice, Konstantinovy Lázně
CO₂ Concentration	375–2,500 mg/l depending on the spring
Water Temperature	33–35 °C — body-warm, no cardiovascular stress
Duration per Bath	15–20 minutes
Frequency	Daily or every second day, 12–15 baths per course
Kurdauer	14–21 days recommended

What Is a CO₂ Bath?

A CO₂ bath uses naturally occurring carbon dioxide gas dissolved in mineral spring water. Unlike artificially carbonated spa baths, the CO₂ in these springs is of geological origin — it has been dissolved in the water for millennia as it percolates through deep rock formations. When the water is used at 33–35 °C — body-warm, not hot — the CO₂ forms tiny, visible pearls on the skin.

The therapeutic mechanism is purely physical: the CO₂ bubbles stimulate skin thermoreceptors, which send a signal via the spinal cord to the blood vessels. The vessels dilate — up to 300 percent of their resting diameter — reducing peripheral resistance. The heart pumps against less resistance; blood pressure drops. This is physiological vasodilation — the body’s own mechanism, triggered by the gas, without any pharmacological intervention.

The co₂ bath has two distinct forms:

The wet CO₂ bath (Mariánské Lázně, Poděbrady, Karlovy Vary, Teplice, Konstantinovy Lázně) — the patient lies in a tub of 33–35 °C mineral water with natural CO₂. The gas bubbles continuously rise from the water and pearl on the skin. The bath lasts 15–20 minutes and is the standard form of CO₂ therapy. The intensity depends on the natural CO₂ concentration of the spring — from 375 mg/l at Teplice to 2,500 mg/l at Mariánské Lázně, which is the highest natural CO₂ concentration of any healing water in Europe.

The dry CO₂ gas bath (Františkovy Lázně) — the patient sits in a sealed cabin with the head outside, breathing normal air. Pure natural CO₂ is introduced into the cabin and acts exclusively through the skin of the body below the neck. Because there is no water, there is no hydrostatic pressure on the circulation — this is the safest form of CO₂ therapy for patients with the most compromised cardiovascular function.

Which Spas Offer CO₂ Baths?

Spa	Country	CO₂ Concentration	Temperature	★
Mariánské Lázně	Czech Republic	Up to 2,500 mg/l — highest natural CO₂ in Europe	33–34 °C	★★★
Poděbrady	Czech Republic	High — from alkaline hydrogen-carbonate springs	33–35 °C	★★★
Karlovy Vary	Czech Republic	350–1,600 mg/l depending on the spring	33–35 °C	★★
Teplice	Czech Republic	375 mg/l — gentle, cardiovascular-safe	33–35 °C	★★
Konstantinovy Lázně	Czech Republic	High — from CO₂-rich hydrogen-carbonate-chloride springs	33–34 °C	★★

Who Can Benefit from a CO₂ Bath?

Condition	Recommended Spa	Mechanism
Hypertension	Mariánské Lázně, Poděbrady	CO₂ at 2,500 mg/l — strongest vasodilation, blood pressure drops within 5 minutes
Coronary Heart Disease	Mariánské Lázně, Poděbrady	CO₂ dilates coronary vessels, improves cardiac perfusion
Peripheral Arterial Disease	Teplice, Konstantinovy Lázně	CO₂ therapy + walking promote collateral vessel formation
Post-Heart Attack	Poděbrady	Gentle CO₂ baths + dosed walking in a dedicated cardiology centre
Cardiac Arrhythmias	Poděbrady, Konstantinovy Lázně	Gentle balneotherapy under cardiac monitoring
Stress-Related Hypertension	Konstantinovy Lázně	Intimate CO₂ therapy in a quiet forest setting

Not suitable for: acute heart failure, unstable angina, recent myocardial infarction (less than 6–8 weeks), severe aortic stenosis, and acute infections. The spa doctor determines individual suitability — co₂ baths are among the safest spa treatments for cardiac patients when properly prescribed.

How a CO₂ Bath Works Step by Step

Before the first bath, the spa doctor measures blood pressure, reviews your cardiac history, and determines the appropriate CO₂ concentration and bath duration. Bring current cardiac reports, a medication list, and recent blood pressure readings.

The CO₂ bath is drawn at 33–35 °C — body-warm, not hot. The temperature is critical: if the water is too warm, it stresses the cardiovascular system; if too cold, the CO₂ does not bubble effectively. The patient immerses up to the chest. Within seconds, the skin reddens — the first visible sign of capillary dilation. Blood pressure is often monitored during the first bath to confirm the vasodilation response.

The bath lasts 15–20 minutes. After the bath, a 20–30 minute rest period follows. The blood pressure reduction persists for four to six hours. In a dry CO₂ gas bath at Františkovy Lázně, the procedure is identical except the patient sits in a cabin with the head outside. CO₂ bath treatment — learn more about the full programme.

What to bring: the spa provides everything. You may wish to bring a book or magazine for the rest period after the bath. Blood pressure medication should be taken as prescribed — the spa doctor will advise on timing relative to the bath.

A Typical Spa Day with a CO₂ Bath

Time	Activity
07:00	Rise — self-measure blood pressure
07:30	Drinking cure — as prescribed
08:00	Breakfast
09:00	CO₂ bath — 15–20 minutes, blood pressure monitored
09:30	Rest period — 20–30 minutes
10:00	Dosed walking — 1–2 km on flat terrain, pulse-monitored
11:00	Cardiac physiotherapy or relaxation therapy
12:30	Lunch
14:00	Massage or second rest period
15:30	Walking — spa park
17:30	Dinner
19:00	Evening walk — gentle, restorative

Frequently Asked Questions