In this Pacific Prime Thailand<\/a> article, we look at the most common Thailand wet season illnesses to watch out for, and what you can do to avoid them.<\/p>\n The Land of Smiles has three official seasons: hot, cool, and wet. The wet season (in other words, Thailand\u2019s flu season) begins around mid-May every year, and continues until mid-October when rainfall starts to become less frequent.<\/span><\/p>\n Thailand recorded between 45,145 and 158,000 dengue cases annually between 2022 and 2024. As of August 2025, Thailand had already reported more than <\/span>38,000 dengue cases and 37 deaths nationwide<\/span><\/a>.<\/span><\/p>\n Dengue Fever usually causes body aches, fever, headache, and a skin rash with red spots. Worryingly, there\u2019s around a 36 percent chance for this wet season illness to develop into Dengue Hemorrhagic Fever (DHF), which is associated with severe symptoms like:<\/span><\/p>\n Those with severe dengue fever must seek medical treatment immediately, as complications can be fatal and lead to circulatory system failure.<\/span><\/p>\n We actually discussed <\/span>dengue fever<\/span><\/a> prevention in one of our blog articles on dengue fever, but here\u2019s a quick recap of the most important precautionary measures people living or traveling in Thailand should be aware of:<\/span><\/p>\n As a contagious viral infection, hand-foot-and-mouth disease spreads through physical contact with the infected person\u2019s bodily secretions. It is common among young children, with potential complications ranging from meningitis, encephalitis, paralysis, and more.<\/span><\/p>\n In most cases, the patient will suffer mild symptoms but will recover in several days. We recommend seeing a doctor if it keeps your child from drinking liquids. See below for a list of symptoms commonly associated with hand-foot-and-mouth disease:<\/span><\/p>\n Avoid close contact with people infected with the disease and using their personal items. It\u2019s also important to wash your hands frequently and only consume thoroughly cooked, steaming hot food.<\/span><\/p>\n Another common disease in Thailand is Pneumonia, which is a wet season illness. Characterized by infection of one\/both lungs, people with pneumonia usually experience physical symptoms such as shortage of breath, clammy skin, fever, chills, cough, and shaking.\u00a0<\/span><\/p>\n Pneumonia can be a side effect of other health conditions \u2013 e.g. asthma. While most cases of pneumonia can be treated successfully, it can be fatal if left untreated, especially among young children, the elderly, and those with weakened immune systems.<\/span><\/p>\n Maintaining good personal hygiene is also key as your hands are in constant contact with different types of bacteria, you should make it a habit to wash them with soap frequently and thoroughly to lower your risk of infection.<\/span><\/p>\n Pneumonia is highly contagious, so it is important that you try to keep others from getting infected as well. If you\u2019re suffering from any of the above-mentioned symptoms, make sure you see a doctor as soon as possible. <\/span><\/p>\n Like dengue fever, Japanese encephalitis is also a mosquito-borne illness that can, in severe cases, lead to inflammation of the brain.<\/span><\/p>\n While the risk of contracting this wet season illness is not very high when compared to the incidence rates of other illnesses\u00a0 such as dengue fever , you are at a higher risk if you live or travel to <\/span>rural areas<\/span><\/a> for a prolonged period of time.<\/span><\/p>\n In Thailand, the disease is more common in the northern region like <\/span>Chiang Mai Valley<\/span><\/a>.<\/span><\/p>\n People infected with Japanese encephalitis will usually develop the following symptoms:<\/span><\/p>\n In severe cases, swelling can develop around the brain, and result in cognitive\/neurological damage.<\/span><\/p>\n The most effective ways of protecting yourself from Japanese encephalitis include preventing mosquito bites (e.g. by using an appropriate insect repellent), and getting the Japanese encephalitis vaccine at least 6 weeks before traveling to a high risk area.<\/span><\/p>\n Leptospirosis is a rare bacterial disease that affects both humans and animals. It\u2019s spread through contact with soil, water, and food contaminated with the blood, urine, or tissue of an infected animal. The disease can be found in dogs, rodents, buffalos, and farm animals.<\/span><\/p>\n You\u2019re more at risk if you spend a lot of time outdoors or work closely with animals. As such, certain occupations, such as farmers, veterinarians, are also more prone to contracting leptospirosis. In severe cases, patients may develop meningitis, kidney malfunction, or even death.<\/span><\/p>\n Common symptoms of leptospirosis include:<\/span><\/p>\n However, it\u2019s interesting to note that some infected persons display no symptoms at all.<\/span><\/p>\n Avoid stepping on puddles as they may be contaminated by animal urine. It\u2019s also a good idea to wear water repellent boots and wear long pants. Most importantly, avoid touching your eyes, ears, and mouth after coming into contact with contaminated substances.<\/span><\/p>\n Influenza remains one of the most common illnesses during Thailand\u2019s rainy season. More than <\/span>373,000 influenza cases and 51 related deaths<\/span><\/a> were reported between January and mid-June 2025 alone, highlighting the continued seasonal impact of the virus.<\/span><\/p>\n Thailand\u2019s wet season also coincides with the country\u2019s peak influenza season. Increased rainfall often leads to more time spent indoors and in crowded environments, which can increase the spread of respiratory viruses.<\/span><\/p>\n Common fly symptoms include:<\/p>\n While many people recover within several days, influenza can lead to more serious complications among young children, older adults, pregnant women, and individuals with underlying medical conditions such as asthma or chronic respiratory illnesses.<\/span><\/p>\n The best form of protection against the flu is to stay healthy and boost your immunity. Regular exercise and a nutrient-rich diet are therefore key. The flu vaccine is also highly recommended, especially if you\u2019re more at risk of developing medical complications arising from flu.<\/span><\/p>\n Malaria remains a health concern in certain remote and forested areas of Thailand, particularly near some border regions. However, the risk is generally very low in major urban and tourist destinations such as Bangkok, Chiang Mai, and Pattaya.<\/span><\/p>\n The disease is transmitted through the bite of infected female Anopheles mosquitoes, which are more active during and after periods of heavy rainfall. The <\/span>World Health Organization<\/span><\/a> and <\/span>CDC <\/span><\/a>warn travelers to take necessary precautions before visiting forested or rural border provinces.<\/span><\/p>\n Common malaria symptoms include:<\/p>\n Symptoms can appear between 7\u201330 days after infection and may initially resemble the flu. Severe malaria can become life-threatening without prompt medical treatment, particularly infections caused by Plasmodium falciparum.<\/span><\/p>\n Travelers visiting higher-risk areas should speak with a healthcare provider about whether antimalarial medication is recommended before departure. Additional preventive measures include:<\/span><\/p>\n Medical treatment for wet season illnesses in Thailand can become expensive, particularly if hospitalization, specialist care, or emergency treatment at private hospitals is required. Ongoing monitoring and follow-up care will also add to the medical costs.\u00a0<\/span><\/p>\n Having <\/span>international health insurance<\/span><\/a> can help provide financial protection and access to quality healthcare throughout Thailand. Depending on your policy, coverage may include:<\/span><\/p>\n![\"Get](\"https:\/\/www.pacificprime.co.th\/blog\/wp-content\/uploads\/2022\/09\/Banner-v3.jpg\")
<\/a><\/p><\/div>\n\nWhen is the Wet Season in Thailand<\/strong><\/h2>\n
Dengue Fever<\/strong><\/h2>\n
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How to Protect Yourself From Dengue Fever<\/strong><\/h3>\n
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Hand-foot-and-mouth <\/strong>D<\/strong>isease<\/strong><\/h2>\n
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How to Protect Yourself From Hand-foot-and-mouth Disease<\/strong><\/h3>\n
Pneumonia<\/strong><\/h2>\n
How to Protect Yourself From Pneumonia<\/strong><\/h3>\n
Japanese Encephalitis<\/strong><\/h2>\n
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How to Protect Yourself from Japanese Encephalitis<\/strong><\/h3>\n
Leptospirosis<\/strong><\/h2>\n
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How to Protect Yourself From Leptospirosis<\/strong><\/h3>\n
Flu<\/strong><\/h2>\n
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How to Protect Yourself from the Flu<\/strong><\/h3>\n
Malaria<\/strong><\/h2>\n
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How to Protect Yourself From Malaria<\/strong><\/h3>\n
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Does Your Expat Health Insurance cover Wet Season Illness?<\/strong><\/h2>\n
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