Although its symptoms are similar to those of many other conditions, you could have a yeast problem if you have these signs.

General symptoms:
Chronic fatigue
Loss of energy
General malaise
Decreased libido

Gastrointestinal symptoms:
Thrush
Bloating and gas
Intestinal cramps
Rectal itching
Altered bowel function

Genitourinary symptoms:
Yeast infections
Frequent bladder infections
Interstitial cystitis

Hormone complaints:
Menstrual irregularities like pain, bleeding, etc.
Premenstrual syndrome
Thyroid dysfunction

Nervous system complaints:
Depression
Irritability
Inability to concentrate

Immune system complaints:
Allergies
Chemical sensitivities
Low immune function

Past history:
Chronic yeast infections
Chronic antibiotic use for infections or acne
Oral birth control pill usage
Oral steroid hormone usage

Associated conditions:
Sensitivity to foods, chemicals, or other allergens
Eczema
Psoriasis
Irritable bowel syndrome
Craving for foods rich in carbohydrates or yeast
Toenail fungus

Source: Textbook of Natural Medicine, Pizzorno and Murray, Churchill Livingstone 1999