Disclaimer: this has not been written by a doctor.
The most common illness for travelers in Central Asia is diarrhea or constipation. Make sure to always wash your hands before eating, ease yourself into the dietary habits of the region by mixing fruits and homemade meals with restaurant food, and pack some basic medicine like Motilium and Imodium for when the shit hits the fan.
Dehydration is a danger for inexperienced outdoors enthusiasts. Drink enough. Avoid unpasteurised milk (it’s the stuff you buy on the market in plastic Coke bottles) or boil it before use. For drinking water, there are several strategies. One is to only drink bottled, boiled or purified water.
The other is to do as the locals do. It’s up to you, know thyself. You can also slowly habituate yourself to the different water quality by taking small sips. In Tajikistan, cholera is endemic, which means you should be extra careful.
Especially in Kyrgyzstan (eg. Song Kol and Tash Rabat) and Tajikistan (Pamir Highway), altitude sickness can happen to anyone. Altitude sickness happens through a rapid ascent and subsequently staying over 2500 m (8200 ft) for more than 12 hours. As a general rule, you should not sleep more than 300-400 m higher than the night before to stay on the safe side. Diamox is a medicine that can help with acclimatising (talk to your doctor). For the Pamir Highway, see the following altitude profiles (1 – 2 – 3 – 4 – 5). For the full lowdown on altitude sickness, check the travel doctor.
Malaria: There are occasional cases of malaria in summer in Tajikistan, in the Khatlon region on the border with Afghanistan (see the area in deep red here). Transmission season generally lasts from May to October. Above 2500m you are safe. (more info at WHO). Bring DEET for travel in the region. If you are going to Khatlon, you should consider antimalarials.
Tick-borne encephalitis: Every year a few people die after contracting tick-borne encephalitis. We advise to get vaccinated if you plan to do any hiking, as popular places like Ala-Archa near Bishkek or the mountains around Almaty and Shymkent are known to harbour this disease.
Hepatitis A: Occurs all over the region and you should be vaccinated.
Hepatitis B: Also occurs all over the region. Vaccinate if you plan on having sex with a new partner, get injections, piercings or a tattoo.
Rabies: Vaccinations are expensive and the chance of obtaining the virus is small, so you should weigh off the risks involved. If you are planning to stay in the countryside for a long time, vaccinating is worthwhile. It’s a terrible disease.
Typhoid: Especially an issue in Tajikistan and Turkmenistan. You should be vaccinated in any case.
DTP (Diphtheria, Tetanus and Polio) and MMR (Measles, Mumps and Rubella): Make sure your inoculations are up-to-date.
The travel clinic website has a good round-up of recommended vaccinations.
Generally a scary affair. There are some hospitals in the main cities which could be said are up to standard, but medicine is definitely still behind versus the rest of the world. Doctors frequently misdiagnose, sometimes on purpose to milk you for money. For any kind of serious illness, locals go to China or India to get treatment. We suggest you do the same for anything that is not super-urgent or easy to fix like a broken leg. Dentists are hit and miss: if you really need one, ask around in the expat community to get recommendations.