Imagine you're a cancer patient in Greece. Now imagine, like more than 25 percent of the population here, you've lost your job. Chances are you'd already be struggling to get medication from the country's crumbling healthcare system. Now capital controls are set to make things even worse.

Pharmacists in Greece fret that it's only a matter of time before essential medicines - most of them imported - start to run out. Buyers in Greece can't send money abroad, and there's only so much leeway the drug companies are likely to give.

The volunteer staff at the Metropolitan Community Clinic in the Athens suburb of Elliniko know all about pressure. They've been a lifeline for the more than 40,000 patients treated, for free, since the start of the crisis. Co-founder Giorgos Vichas says that as bad as things are now, they could get dramatically worse if the banks stay closed.