Summer, a season marked by its characteristic warmth and the vibrant exuberance of nature, is associated with specific climatic energies that profoundly influence human health according to traditional medical systems. In traditional Chinese medicine (TCM), the summer season corresponds to the Fire element and is dominated by Heat as a climatic factor. The human body, viewed as a microcosm of the universe, is intimately connected to these seasonal changes. While the body possesses adaptive abilities to these shifts, abnormal or excessive climatic changes, or a weakened constitution, can lead to specific seasonal illnesses, making understanding TCM summer health principles crucial for maintaining well-being.
The primary external pathogenic factor associated with summer is Summer Heat (Shǔ). Summer Heat is considered a Yang pathogen, possessing an upward and outward dynamic. Its nature is flaming heat, which tends to consume the body’s Qi (vital energy) and Yin (fluids and cooling vital substances). Unlike other external pathogenic factors which can occur year-round, Summer Heat is uniquely and exclusively a phenomenon of the summer season.
Summer Heat frequently combines with Dampness, especially because summer is often accompanied by rain and humidity. This combination gives rise to Summerheat-Dampness patterns, which manifest differently from pure Summer Heat conditions and can impact seasonal wellness.
Common Summer Ailments in Traditional Medicine
Several health issues are identified in the sources as being particularly prevalent or exacerbated during the summer months due to these climatic influences:
- Heat Stroke and Sunstroke: These are acute and severe conditions directly caused by exposure to excessive sun or working under high temperatures. Symptoms include headache, dizziness, spots before the eyes, fatigue, nausea, vomiting, and early-stage perspiration. Later developments can involve high fever, increased pulse and respirations, flushed face, breakdown or excess of perspiration, facial pallor, muscular spasms, and pain. In severe cases, Summer Heat can invade the pericardium (the sac around the heart), causing clouding of the mind, unconsciousness, or even coma. This intense heat can also generate internal wind, leading to cramps and spasms.
- Gastrointestinal Disorders: The summer season is frequently linked to digestive issues. Summerheat-dampness assailing the stomach and intestines is a common cause of abdominal pain and diarrhoea, often involving blood and mucus. Improper or unclean food intake can also generate damp-heat in the intestines, prevalent in summer. Diarrhoea, specifically “summerheat-damp diarrhoea,” is a common symptom. Cholera is noted as a disease occurring in summer and fall. Drinking unboiled water and inadequate food hygiene in hot summer months, especially during busy agricultural periods, contributes to rampant intestinal tract diseases like dysentery. Vomiting can also be a symptom of summerheat or summerheat-dampness.
- Fevers: High fever is a characteristic symptom of Summer Heat invasion. Tidal fever, particularly in the late afternoon, can be seen in internal heat patterns or sometimes with Summerheat-Dampness. There is also mention of “summer fever in children,” a pattern characterized by long-term mild fever in the summer, accompanied by vexation, thirst, and increased urination.
- Dehydration and Fluid Imbalances: Summer Heat consumes fluids and Qi. This can lead to symptoms like profound thirst (often with a desire for cold drinks), dry mouth and throat, scanty and dark urine, or alternatively, excessive sweating that depletes fluids. Lack of sufficient perspiration in summer heat can lead to issues like prickly heat or even intermittent fever in the fall.
- Fatigue and Weakness: Summer Heat expends Qi, leading to lassitude, listlessness, and fatigue. Damage to both Qi and fluids by Summer Heat results in fatigue and weak breathing.
- Skin Disorders: Prickly heat (miliaria), caused by inadequate perspiration in unduly hot weather, is a commonly seen skin ailment in summertime. Impetigo, or “yellow fluid sores,” mostly occurs in summertime and is due to damp heat attacking the skin. Skin irritations can arise from excess perspiration. Heat and Fire can also cause eruptions and rashes.
- Mental and Spirit Disturbances: Summer Heat easily harasses the Heart and disturbs the spirit (Shen). This can manifest as restlessness, irritability, vexation, delirium, or in severe cases, clouding of the spirit, unconsciousness, or coma. Chen, in their book The Invention of Madness, notes a case where excessive wetness transformed into heat in a “scorching hot” summer resulted in “vigorous heat and confused madness”. Li Dong-Yuan, a prominent physician of the Jin-Yuan dynasties, also stated that when a disease worsens during the months of summer-heat, it can be transmitted to the kidneys and liver, potentially affecting the heart and causing irritability.
- Respiratory Issues: Breathing problems such as asthma and bronchitis are noted to worsen during the wet summer (July and August), corresponding to environmental qualities that aggravate what Tibetan medicine refers to as Loong energy (akin to wind or movement). Summer Heat can damage the Lung network vessels, potentially causing hemoptysis (coughing up blood). Lung heat caused by Summer Heat can lead to cough with yellow phlegm.
- Myocarditis: Outbreaks of viral myocarditis (inflammation of the heart muscle) are most common in the summer and early fall.
- Worsening of Existing Conditions: Heat in general can worsen existing conditions. Damp-heat conditions are more frequently encountered or exacerbated in seasons with hot temperatures and dampness.
Perspectives from Tibetan Medicine
In Tibetan Medicine, the Tibetan lunar calendar divides summer into “dry summer” (May-June) and “wet summer” (July-August). In dry summer, light and dry environmental qualities, similar to Loong energy (one of the three principal energies), can lead to Loong accumulation. In wet summer, cooler rain and wind can aggravate Loong, manifesting as breathing problems and joint issues. During the wet summer, oily environmental qualities can lead to mKhris-pa (bile energy, one of the three principal energies) accumulation, which then aggravates and manifests as disorders like headaches and high blood pressure in the warmer, oily autumn.
The wisdom embedded in these traditional medical systems underscores the dynamic interplay between our internal environment and the external climate. Recognizing the specific challenges posed by summer’s heat and humidity allows for proactive adjustments in diet, lifestyle, and daily activities. By aligning ourselves with the season’s energetic profile, as these ancient traditions advise, we can better navigate its potential pitfalls and cultivate resilience, fostering a greater sense of harmony and well-being throughout the warmer months and beyond.