Internal divisions were came from various sides. For starters, numerous and various ethnic groups started becoming nationalized more and more and wanted to gain their independence. This was seen in areas such as the Balkans where Ottomans started losing more and more influence. They also had problems with their own people because of a need of modernization which was severely lacking in the Ottoman empire which was underdeveloped compared to other European states and empires.
External pressures were mostly financially related. At one point in time, the Ottoman empire had such high national debt that paying the annual rates took more than half of the revenue from the yearly budget. Their armies were also dwindling so it was easy for others to remove them from their territory such as what Egypt did after a few wars.
