Can stress cause a woman to have unusual vaginal bleeding?

A friend of mine told me that she suddenly stood up and felt a "gush." She said she bled for two hours straight. Then zilch. She has be unusually stressed out lately, not getting enough sleep, have had some soreness surrounded by her shoulder due to her muscles being adjectives tensed up (for about a month now). Her doctors do not presume that this is something to worry almost; they thought maybe she be having an unusually strong extent. But she got her regular length 4 days later.
Answers:

My time come and go?

Abnormal vaginal bleeding
What is unexpected vaginal bleeding?

The usual cause of vaginal bleeding is menstruation (the monthly period). However, any vaginal bleeding to be precise not normal menstrual bleeding or mid- cycle spotting (which commonly occurs during the first few months of taking the oral contraceptive pill) may be uncharacteristic and must be investigated. This is because it may be a sign of a problem within the vagina, uterus (womb) or ovaries. This includes irregular or excessively indigestible menstrual bleeding, and any vaginal bleeding in a woman who has passed the menopause.

In young girls, the first few periods can be irregular and of varying degree of heaviness, and this is not phenomenal. Around the time of the menopause, menstrual bleeding often become irregular, and again this is not abnormal.

HRT (hormone replacement therapy) may also exact harmless bleeding in postmenopausal women who hold stopped having period.

What causes out of the ordinary vaginal bleeding and who is at risk? Abnormal vaginal bleeding may occur between the run of the mill menstrual bleeds (intermenstrual bleeding) or it may take the form of unusually immense menstrual bleeding (menorrhagia). In postmenopausal women, it may develop after a number of years minus any vaginal bleeding. It can be caused by several things, including:

hormone imbalances,
injury to the vagina or vulva,
sexual invective,
infection in the uterus,
polyps and fibroids (benign growths) in the uterus,
cancer of the cervix,
cancer of the uterus,
some cancers of the ovaries,
complications of an rash (possibly
unknown) pregnancy, for example,
ectopic pregnancy or threatened miscarriage.
Hormonal imbalances are by far the most adjectives cause, and the problem usually occur during the reproductive years.