When sangs discover they are a sang they call it an "Awakening"

Signs of a Sanguinarian Awakening

A sanguinarian vampire is commonly created by being infected by another vampire, but some vampires are genetically prone to becoming a vampire.

A latent sanguinarian vampire will come to his awakening later in life, usually around the teen years, but a latent vampire can develop signs of vampirism at any age and of any religion.

The basic signs of a vampire awakening can be frightening and even painful for someone who isn’t aware of what’s happening.

Extreme and unquenchable thirst (unless blood is consumed, on accident and usually their own in the beginning)

The taste of blood creates more energy

Feelings of euphoria, relaxation and heightened senses when near blood

An insatiable desire to consume blood

Oversensitivity to sunlight

Either difficulty tanning or easily tanned

Feelings of anger and rapid mood swings

Psychic abilities

Empathic thoughts around others

New food allergies

Chronic and cycling bouts of depression

Migraines and possible GI problems

Overemotional or melodramatic

Heightened physical senses (hearing, smell, taste and touch)

Tendency to be more active at night

Withdrawal from family and friends

Sudden strength

Sanguinarian vampires usually do not experience levitation, shape-shifting or other physical powers.

http://vampireunderworld.com/vampirism/sanguinarian-awakening/