It's true...any shock to your system whether it be emotional or physical stress or a big change in diet can result in temporary hair loss. It's often difficult to discover precisely what triggered the hair loss as the loss is usually seen about 4 months after the event that caused it. The good news is that it's usually temporary and will start growing back soon.
If it continues, it might be good to go see your doctor. Hair loss can also be a symptom of other problems such as hypothyroid or vitamin/mineral deficiency.