Six years of conflict have brought the Syrian health service, once one of the best in the Middle East, close to collapse. Fewer than half of the country's hospitals are fully functioning. Around 200 children visit the Children's Hospital in Damascus every week, with more than 70 percent from outside the capital.

Young cancer patients wait for treatment at Damascus Children's Hospital. Local and World Health Organization officials blame Western sanctions for severely restricting pharmaceutical imports, even though medical supplies are largely exempt from measures imposed by the United States and European Union.

Cuts in health expenditure by the Syrian government fighting a hugely expensive war, a drastic fall in the value of the currency and indirect effects of the sanctions are all deepening the misery of patients who need foreign-made drugs. Before the conflict, Syria produced 90 percent of the medicines it needed but anti-cancer drugs were among those where it traditionally relied on imports.

Nurses taking care of a sick child. The World Health Organization in Syria, says medicine imports have been hit by significant cuts in the government's health budget since the war began in 2011. Adding up tot hat is a 90 percent drop in the value of the Syrian pound, which has made some pharmaceuticals prohibitively expensive.

"The impact of economic sanctions imposed on Syria heavily affected the procurement of some specific medicine including anti-cancer medicines," says Elizabeth Hoff, the WHO representative in Syria. "The sanctions were preventing many international pharmaceutical companies from dealing with the Syrian authorities as well as hindering foreign banks in handling payments for imported drugs."

Cancer patient Fahd plays with his mobile phone while his mother sits by his bed. Both the U.S. and EU sanctions include exemptions for medicines and other humanitarian supplies. However, by clamping down on financial transactions and barring much business with the Syrian government, the sanctions are indirectly affecting trade in pharmaceuticals.

One private charity, Basma, is trying to help out by funding cancer drugs for poor families. The proportion of patients who need assistance has risen from about 30 percent to nearly 80 percent since the war began, according to executive manager Rima Salem. Salem finds the delays in treatment worrying. "A child with cancer might die waiting for his turn to get treatment," she said.

Syria has been engulfed in a devastating civil war since 2011 after Syrian President Bashar Assad lost control over large parts of the country to multiple revolutionary groups. The conflict has since drawn in foreign powers and brought misery and death to Syrians.

Syria's army, officially known as the Syrian Arab Army (SAA), is loyal to Syrian President Bashar al-Assad and is fighting to restore the president's rule over the entire country. The SAA has been fighting alongside a number of pro-Assad militias such as the National Defense Force and has cooperated with military advisors from Russia and Iran, which back Assad.

Turkey, which is also part of the US-led coalition against IS, has actively supported rebels opposed to Assad. It has a tense relationship with its American allies over US cooperation with Kurdish fighters, who Ankara says are linked to the Kurdistan Workers' Party (PKK) fighting in Turkey. Turkey has launched multiple military offensives targeting Kurdish militias.

The Kremlin has proven to be a powerful friend to Assad. Russian air power and ground troops officially joined the fight in September 2015 after years of supplying the Syrian army. Moscow has come under fire from the international community for the high number of civilian casualties during its airstrikes. However, Russia's intervention turned the tide in war in favor of Assad.

A US-led coalition of more than 50 countries, including Germany, began targeting IS and other terrorist targets with airstrikes in late 2014. The anti-IS coalition has dealt major setbacks to the militant group. The US has more than a thousand special forces in the country backing the Syrian Democratic Forces.

The Free Syrian Army grew out of protests against the Assad regime that eventually turned violent. Along with other non-jihadist rebel groups, it seeks the ouster of President Assad and democratic elections. After suffering a number of defeats, many of its members defected to hardline militant groups. It garnered some support from the US and Turkey, but its strength has been greatly diminished.

Fighting between Syrian Kurds and Islamists has become its own conflict. The US-led coalition against the "Islamic State" has backed the Syrian Democratic Forces, an alliance of Kurdish and Arab militias. The Kurdish YPG militia is the main component of the SDF. The Kurds have had a tacit understanding with Assad.

"Islamic State" (IS) took advantage of regional chaos to capture vast swathes of territory in Iraq and Syria in 2014. Seeking to establish its own "caliphate," IS has become infamous for its fundamentalist brand of Islam and its mass atrocities. IS is on the brink of defeat after the US and Russia led separate military campaigns against the militant group.

IS is not the only terrorist group that has ravaged Syria. A number of jihadist militant groups are fighting in the conflict, warring against various rebel factions and the Assad regime. One of the main jihadist factions is Hay'at Tahrir al-Sham, which controls most of Idlib province and has ties with al-Qaeda.

Iran has supported Syria, its only Arab ally, for decades. Eager to maintain its ally, Tehran has provided Damascus with strategic assistance, military training and ground troops when the conflict emerged in 2011. The Iran-backed Lebanese Shiite militant group Hezbollah also supports the Assad regime, fighting alongside Iranian forces and paramilitary groups in the country.