Easy : Generally between 900 and 2000 meters with plenty of ups and downs. Travellers need to be regular walkers to fully enjoy this experience. It is possible, however, to design "easy and short" three or four day treks with only two to five hours walking per day.

Moderate : Possibly involving side trips to higher elevations between 900 and 3000 meters.

Moderate to Strenuous : Reasonably demanding trekking at altitude up-to 4000 meters with trips to higher elevations and could include treks away from villages on ill-defined mountain trails.

Strenuous : Treks in other areas treks of demanding nature, require all participants to be fit and in excellent health, often in remote alpine areas and sometimes reaching altitudes over 5500 meters and high pass crossing over.

Alpine : These are extremely demanding treks, sometimes in very remote areas on rough terrain, and could include (in Nepal) climbs of one or more of the "trekking peaks" (maximum altitude, Mt. Mera at 6654 meters). Participants should have at least a basic knowledge of the use of crampons and ice axe, though first time climbers may be accepted on some of the "easy" routes. Medical certificates are required for acceptance into these climbing treks.

Normally a trek is not an extreme sport, even you might do so if you whish. Trekking usually also does not require you to be a very sportive person, nor needs a specially training for long time before undertaking a trek itself. Usually one, who does some excursions before coming to Nepal for a longer trek, will not encounter problems related to trekking. There are however some general points to consider for trekking in the Himalayas:

Trekking where and when : Generally it's considered to trek between September and May, but actually a trek can be done all throughout the year. Usually the sights are very good from October to April, with preference on the fall season.
Depending on the particular interest, a trek in the Khumbu or Annapurna regions can be interesting also throughout the monsoon period, where many flowers bloom and often the rains specially in the Annapurnas above Pisang and Tuchucke are pretty few for the time and you are nearly alone like in a remote trek! Generally according to climate and other reasons specified above, you might divide the timing and zones of interest as follow:

Dolpa, Mustang, Humla, Mugu : This Trans Himalayan areas, out of the reach of the monsoon (even if disturbances are possible), are best throughout April to October, while from November to March you can't usually go to this areas due to the harsh winter and snow in the areas.

Kanchenjunga, Manaslu, Makalu : Are very beautiful throughout end of September to mid November and again through March to May, while in the winter from December the high passes (specially Manaslu) can hamper the crossing of the passes.

Everest, Langtang, Annapurna and most other areas : suitable from mid September to May (some passes like Thorong La or Ganja La however can be closed for some days in the winter months of December to February). The monsoon period indicates to a trek in the first category or to a tour in Tibet, where the rains are much less or absent.
When you come for a trek during the monsoon period, be prepared for rains, delays on flights inside Nepal and leeches. I personally like trekking in the summer in the Annapurnas and Everest region pretty much; I do carry an umbrella and high trekking boots.

There are mainly two ways in which trekking in Nepal can be done :

Nepal Teahouse/Lodge Trek : Teahouse trek can be done only on some very popular trekking routes such as Annapurna, Everest and Langtang region. We offer modest accommodations and reasonable standard of food at teahouse and lodges all along the trails. A guide and some porters take care of leading the trek and carrying the luggage and equipments.

Fully organized camping trekking : On a tented trek we take along all the necessary food and camping equipment. This way we are able to set our own pace and travel through places untouched by mass tourism. A fully organized trek is one, which is self-sufficient. There are guides, cooks, porters or yaks to take care of all the technical and logistical aspects of the trip. Every day our staff will set the camp and our well trained, professional cooks prepare the delicious semi-western type meals. Our trekking guide acquaints you with the local culture and customs.

The following equipment lists are suggested and essential for both types (camping & teahouse) treks in the Himalayas country in Nepal. Make use of this list as a guideline proposal. Some of the Trekking equipments can be hired or bought in the many adventure shops in Katmandu.

Kitbag : For all the treks your gear that is carried by the porters or yaks is best packed in strong duffel. A simple design without wheels and without foldable handles is best. You can buy in Kathmandu.

Sleeping bag : Down-filled bags are better. Beg, borrow or steal a good one (ie 4-5 season) because high altitude nights will be cool. Good down is fluffy, light and thick. A muff (an extra section around the neck) makes a big difference to the overall warmth of a bag. Reasonable sleeping bags are cheaply available for rent in Kathmandu.

Sleeping bag liner : Cotton, silk or fleece. Saves washing your sleeping bag and adds warmth. Cotton or silk ones can be made in Kathmandu but are more easily bought from home. Fleece ones are readily available in Kathmandu.

Daypack : This should be comfortable and a good waist band that transfers some of the weight to the hips is most important. It needs to be big enough to take a jacket, fleece, water, camera and odds and ends.

Boots : For the trek you need comfortable feet. Good boots have: good ankle support, plenty of toe room for long descents, a stiff sole to lessen twisting torsion, and are light because with every step you lift your boot up. Look at the inner lining - leather is good and Amarelle is even better, a material that eats smelly feet bacteria. Good lightweight trekking boots or light all leather boots are perfect. Boots must be lightly worn in before trekking and this should include some steep hills to show up trouble spots. The longer the trek, the better the boots you need.

Socks : In the low country your feet will be warm or even hot while walking so quality cotton mix sports socks are best. Three to four pairs are enough. Thick trekking socks are better for higher up and cool evenings, four pairs. Mostly modern trekking boots fit snugly so wearing two pairs of socks at the same time is impractical.

Fleece Jacket : Most trekkers consider this essential, but alternatives are a thick thermal top or a light down jacket. In Kathmandu you can get almost any sort of fleece you need.

Down Jacket : If you don't already have a jacket, they are easily rented in Kathmandu. A down jacket is the best option, although a vest can also be brought along.

Wind/Rain Jacket : Plastic ponchos or non-breathable raincoats are not suitable. Gore-tex or similar jackets are recommended for treks over passes or climbing trips. Lighter jackets should be a second jacket, easy to throw in the daypack for warmer days.

Thermal Shirts/Underwear : Good thermals, both tops and bottoms, are one of the secrets to cold weather trekking comfort. Expedition-weight thermals are the most versatile and can be worn as your high altitude trekking top or under pants on extremely cold days. Zip-up tops are great for changeable weather.

Nightwear Thermals : Silk-weight is lightest and warm, mid-weight is perfect. Great for warm nights in the sleeping bag!

Fleece/Sweatpants : Great for the chilly evenings, thicker is better (except for when the stoves in the teahouses really heat up.

Day-wear shirt : T-shirts are popular but a cotton shirt or mixed yarn travel shirt is more versatile. The collar protects the back of your neck and the sleeves can be rolled up or down. Take two or three so you can swap damp for dry.

Trekking paints : You will live in these. Light material, loose and dark-coloured is best. You can survive with only one pair, although two is better.

Wind pants : If your trekking pants are reasonably windproof then special wind pants are not needed. If you do bring a pair, it is not necessary to have Gore-tex. Similar, non-waterproof is quite OK.
Underwear 4 to 7 pairs.

Sunglasses : Suitable for snow, it’s bright up there, but specialized glacier glasses with side pieces are not needed. Contact lens wearers report very few problems except cleaning them in the conditions. Ski goggles are unnecessary.

Mittens/Gloves : A good pair of wind-proof gloves is essential. Available in Kathmandu for cheap if you don't have a pair.

Water bottle : Should be one liter or more in capacity, take boiling water and be leak-proof. Nalgene or a similar brand, or European fuel bottles, are best. You need at least 2 water bottles, or at least 1 water bottle in addition to a Camelback or hydration system. Naglene's are great, available in Kathmandu, real or fake.

First aid kit : We carry one with aspirin, Paracitamol, Ibuprofen, decongestants, lozenges, various antibiotics for Nepalese varieties of diarrhea and chests infections, Diamox, antiseptic, antihistamine cream, rehydration, bandages and band-aids, tough blister tape (but not moleskin). You should bring any personal medicines that you need.

Water purification : A bottle of iodine tablets such as Potable Aqua, Polar Pur or Couglans. We mostly use to water from the lodges but occasionally take water from the streams. The use of mineral water is discouraged from an environmental point of view, but is available everywhere.

For camping trips, we provide all the tents, a foam mattress each, all the cutlery and utensils, cooking pots, stoves; candles/kerosene lantern, tables and stools, kitchen tent, dining tent and toilet tent; all the main meals while trekking but not snacks; and the best service we can manage.