What are the difficulties of Kanchenjunga Circuit Trek?

Kanchenjunga circuit trek is one of challenging high altitude treks in remote corner of eastern Nepal. It is probably the best "well-kept" secret of Himalayas in Nepal. The trekking trial takes you to the foot of Kanchenjunga (8,586m), the third highest mountain in the world which shares its eastern border with India's Sikkim and northern to husky Tibet.