Balneotherapy of patients with rheumatoid arthritis (RA) has been done empirically from ancient times. As a matter of fact, the pain and stiffness are significantly relieved by bathing in a hot spring. The mechanism of action, however, remains still unclear in some points. The authors have pointed out some of the mechanisms, by which RA patients were influenced from spring water bathing.
1) Vascular dilatation. Gas containing hot springs, such as CO₂ spring or H₂ S spring, have vasodilating action on peripheral blood vessels, which increases the blood circulation, resulting in the acceleration of metabolism and the improvement of pain and stiffness.
2) Stimulation on the adrenocortical hormon secretion. Urinary 17-KS excretion increased significantly after serial bathing in hot spring water, especially in sulfur containing spring water, indicating the stimulatory effect on the adrenocortical function.
3) Stimulation on the sympathetic nerve. Plasma norepinephrin levels were elevated during the bathing either in a hot spring or in a cold spring water, although the elevation was much higher in a cold spring water. This may suggest the stimulatory effect of spring water bathing on the sympathetic nerve function.
4) The effect on plasma prostaglandin levels. Plasma prostaglandin levels were concentrated into around the mean level after 3 weeks of serial bathing in a hot spring water.
5) The effect on plasma cyclic AMP levels. Plasma cyclic AMP levels were elevated significantly after 1 week of serial bathing in a cold spring water, but returned to the initial levels after 3 weeks of the serial bathing.
6) The effect on plasma neuropeptide levels. Plasma beta-endorphin levels were lower in RA patients and they were insignificantly elevated by the bathing in a hot spring water. Both the leucine-encephalin and methionine-encephalin levels were unchanged by the bathing, although the initial levels were both within normal ranges in RA patients.
7) The effect on connective tissue metabolism. Urinary excretion of the total hydroxyproline was higher in RA patients, and it was decreased after the bathing in a hot spring water containing sulfur. Serum monoamine oxidase activities, on the other hand, was lower in RA patients, and they were elevated after the bathing in hot spring waters.
8) The effect on the autonomic nerve function. Abnormality of the autonomic nerve function indicated by the coefficient of variance of R-R intervals in EKG was much more found in RA patients than in healthy controls, and it was improved significantly after 4 weeks of serial kinetic bathing in a simple hot spring water.
In spite of the above mentioned beneficial effects on RA patients, bathing in either hot or cold spring water has shown no effect on the inflammatory activity of RA, but only shown ameliorating effects on the pain and stiffness, just like an effect of non-steroidal anti-inflammatory drugs. It should be recommended, therefore, to use hot spring water not only for relieving pain and stiffness, but also for positive rehabilitation exercise.

Criteria for balneotherapy have not been established in rheumatoid arthritis (RA) so far. The body temperature, or erythrocyte sedimentation rate (ESR) is still inconclusive as the standard. We found that urinary hydroxyproline (Hy-pro) may be one of the standards for balneotherapy of RA patient.
1. Urinary hydroxyproline
Daily urinary Hy-pro excretion was significantly higher in RA (41.2±23.3mg/day in 20 cases)
than in control subjects (28.2±14.6mg/day in 22 cases).
In 9 RA patients urinary Hy-pro excretion was decreased significantly after bathing in Konya thermal mud at 42°C for 15-20 minutes, while it increased after the bathing in a systemic lupus erythematosus patient.
On the other hand the urinary Hy-pro excretion was not changed essentially in 5 RA patients who did not take the bathing but rehabilitation exercise as shown below.
Effect of hot spring bathing on urinary Hy-pro excretion
Desease NO Urinary Hy-pro (mg/3hrs)
Before After
RA 9 4.2±2.4 2.1±1.1*
SLE 1 0.4 3.8
RA 5§ 2.1±0.4 2.3±0.4
* p<0.05. § they did rehabilitation exercise only.
From the above results it was concluded that urinary Hy-pro excretion was decreased by the balneotherapy in RA patient, suggesting anti-inflammatory action or stabilizing effect on collagen of the balneotherapy in rhematoid process. On the other hand it was considered that the urinary Hy-pro may serve as a standard for balneotherapy of RA. If it increased after a balneotherapy the patient may have no indication of the therapy.
2. Erythrocyte sedimentation rate
Effect of hot spring therapies on ESR was investigated in 114 RA patients. Improvement of ESR was observed in 30% of RA patients with ESR over 100mm/hr and in the patients with abnormal ESR under 59mm/hr the improvement was found in 31%.
It was concluded, therefore, that ESR is not always a standard for balneotherapy of RA.
3. RA with amyloid nephropathy
Renal function was aggravated after thermal bathing in a RA patient with amyloid nephropathy. Balneotherapy, therefore, must be done very carefully in such patient.

It is well known that spa therapy is quite useful for the so-called life-style related diseases. It is therefore speculated that the number of aged people to be cared by the public insurance of elderly care may be less in spa districts than in non spa districts. As a matter of fact it was demonstrated in Oita prefecture that the number of aged people qualified for receiving the care was significantly less in Beppu city and Yufuin town which are well known as spa resort than in the surrounding non spa city or towns.
This report is the result tallied up on the data from 38 prefectures all over Japan, regarding the number of aged people and hot springs. Although the ratio of number of aged people qualified for receiving the care to all aged people over 65 y-o is quite different among both the prefectures and the cities or towns under the same prefecture, the tendency of lower ratio in spa cities or towns than in the others was observed. It suggests the more prospective study is necessary on the effects of spa bathing on ADL disorders of aged people.

The effect of Artificial CO₂-bathing was compared with that of placebo bathing on patients with rheumatoid arthritis (RA). A large tablet containing sodium bicarbonate and citric acid, which is called Bub, was used to make CO₂ gas as it dissolves in water bath. A placebo tablet, which is quite same in the appearance, has the substrate only and makes no gas. So the trial was performed by single blind method.
Forty two RA patients (definite or classical) were tested by single bathing and other 40 RA patients, by serial bathing of 30 days (once a day). After a single bathing grip strength of the patients increased significantly in both groups, but more significantly in Bub group (p<0.01 vs p<0.05). The joint tenderness also reduced significantly after a single bathing in both groups, almost equally. However plasma β endorphin levels were little changed after single bathing in both groups.
By serial bathing of 30 days, Lansbury's activity index, ADL score, and pain score were all changed insignificantly in each group. However Bub group showed a tendency to improve in the 3 parameters, whereas placebo group did a tendency to deteriorate.
From the above results it was considered that artificial CO₂-bathing may exert more beneficial effects on RA patients, as compared with plain water bathing.

Effect of balneotherapy is said to be obtained by continuous bathing in hot spring for 2-4 weeks. However, a short staying at spa for bathing therapy is quite usual in Japan nowadays. So we conducted an investigation on the effect of bathing therapy at spa for 3-7 days (short group), comparing with the effect of the therapy for 14 days or more (long group), through the collaboration of balneologists in all over Japan. The total of 215 cases, having rheumatic, cardiovascular, metabolic, psycho-neurological, postoperative, skin or digestive diseases, of whom 135 were in the short group and 80, in the long group, were analysed for the influence of spa therapy on the patient's quality of life (QOL). Both the severity of disease by doctor's evaluation through visual analogue scale method and the patient's QOL state assessed by patient through the Face Scale method were improved significantly in both groups after the spa therapy. The disease severity and the patient's QOL state at the end of spa therapy were not changed significantly thereafter through 1 month in both groups. Patient's activities of daily living (ADL), appetite, sleep, pain, itch and fatigue, which will make up the patient's QOL, were also improved significantly after the spa therapy, if they had been disturbed or present, in both groups. All these states at the end of spa therapy were not changed significantly at 1 month after the end of spa therapy in both groups. These results may substantiate the rightfulness of patient's assessment of QOL. The tendency to normalization was found in the body weight, blood pressure and passage too after the spa therapy in both groups. A skin rash, itching or slight thermal crisis was observed in 13 cases as the side effects of spa therapy. None of them was serious. From the above results it is concluded that a short staying spa therapy for 3-7 days is effective as well as the standard long therapy on patient's QOL, and the effects last about 1 month long at least.