Yes they can, pheromones are released by both males and females and they can effect the mood and behavior of both genders. Postpartum depression can actually make the male depressed as well just due to the hormone drop.
Prolactin is a hormone that acts directly on the mammary glands to produce breast milk. This happens when a woman because pregnant, and when a woman is pregnant, the body reaches high levels of estrogen. Thus, increased levels of estrogen will directly increase levels of prolactin.
If a women is not dieting right it can cause her hormone levels to do down. If the hormone levels are low it will be harder for her to get pregnant.
When calcium levels increase, parathyroid hormone decreases. When calcium levels decrease, parathyroid hormone increases. This is known as a negative feedback system.
Since it is caused by an increase in melanin related to in increase in estrogen it is possible for it to be caused by an increase in estrogen in the absence of pregnancy; however if you have been pregnant in the past and it faded it can come back related to exposure to sun or any variation in female hormone levels.
calcitriol
serum calcium levels increase
calcitriol
This can be caused by insufficient hormone levels.
Pregnancy can also be detected through a blood test
Glucagon is catabolic and increases blood glucose levels, insulin is anabolic decreases blood glucose levels.
There are several hormone which serve to raise blood glucose levels. Some examples include cortisol, epinephrine, glucagon, and growth hormone.
As long as she is not pregnant, ovulating, or menstruating then yes. Hormone levels may increase at these times, which would be a dead giveaway. Otherwise, yes.