What is the cure and cause of embolism (blood clot) in her leg and one in each lung. now a lung has collapsed?

Blood thinners.: Cause can be from medications(birthcontrol), inactivity or genetic predispositions. Many causes and need to review with her doctor.Treatment depends on severity. If compromised blood pressure possible clot breaker. Rarely used anymore unless unstable pt. Typically blood thinners to prevent clot from getting bigger. Oral and injectable available. Not sure about collapsed lung?Could have many meaning.