Dehydroepiandrosterone (DHEA) is a steroid hormone precursor primarily generated by the body’s adrenal glands, located just above the kidneys. This hormone acts as a building block for more potent sex hormones like testosterone and estrogen. When blood work shows an elevated DHEA level, it indicates a potential underlying hormonal imbalance. While a high DHEA level is a significant indicator of androgen excess—a key feature of Polycystic Ovary Syndrome (PCOS)—it does not automatically confirm the diagnosis. Further investigation is necessary to determine the specific source and cause of the hormonal imbalance.
Understanding DHEA and Androgens
DHEA is classified as a weak androgen precursor that must be converted in peripheral tissues to become biologically active. The adrenal glands produce both DHEA and its sulfated form, DHEA-S (Dehydroepiandrosterone sulfate). DHEA-S is the more stable and abundant form in the bloodstream, making it the marker most commonly tested in clinical settings. Because DHEA-S has a significantly longer half-life and lacks the strong daily fluctuations of unconjugated DHEA, its measurement is a reliable indicator of adrenal hormone output.
The vast majority of circulating DHEA-S originates from the adrenal glands, specifically the zona reticularis layer of the adrenal cortex. Only small amounts come from the ovaries or testes. This adrenal output contributes to the body’s overall pool of sex steroids. Once circulating, DHEA-S can be converted into androstenedione, which then acts as a direct precursor to testosterone and, subsequently, estrogen. The concentration of this hormone naturally peaks in young adulthood before gradually declining with age.
How Elevated DHEA Relates to PCOS
The presence of high DHEA-S is a direct indicator of hyperandrogenism, a required component for a PCOS diagnosis under most accepted criteria. Hyperandrogenism is the physical or biochemical evidence of excessive male hormones in women, and DHEA-S confirms this state. The elevation signals that the adrenal glands are overproducing their androgen precursor, adding to the total androgen load in the body.
In women with PCOS, this adrenal hyperandrogenism is thought to result from an exaggeration in adrenal steroidogenesis. The adrenal glands exhibit a heightened response to stimulation by adrenocorticotropic hormone (ACTH), leading to increased DHEA-S output. This mechanism distinguishes adrenal-driven excess from ovarian-driven hyperandrogenism, where the ovaries produce too much testosterone and androstenedione.
High DHEA-S is only one potential feature of PCOS and is not observed in every patient. Studies indicate that approximately 20% to 30% of women diagnosed with PCOS exhibit elevated DHEA-S levels. The majority of women with PCOS have normal DHEA-S but may have elevated testosterone or other androgens produced by the ovaries.
The elevated DHEA-S contributes to common PCOS symptoms such as hirsutism (excess body hair), acne, and sometimes hair thinning. While the adrenal contribution is significant in a subset of patients, the diagnosis of PCOS requires the exclusion of other conditions that cause similar hormonal profiles. A high DHEA-S level acts as a strong biochemical flag, prompting a deeper clinical investigation rather than serving as a definitive diagnosis.
Conditions That Also Raise DHEA Levels
An elevated DHEA-S level requires a thorough medical evaluation because several conditions besides PCOS can cause this hormonal shift. Since DHEA-S is predominantly produced by the adrenal glands, a high result suggests a problem originating there. The most common differential diagnosis is Non-classic Congenital Adrenal Hyperplasia (NCCAH).
NCCAH is a genetic disorder causing a deficiency in the 21-hydroxylase enzyme, which leads to a buildup of steroid precursors like 17-hydroxyprogesterone. This buildup is shunted into the androgen pathway, resulting in the overproduction of DHEA and DHEA-S. Because NCCAH presents with symptoms nearly identical to PCOS—such as hirsutism and menstrual irregularities—it must be ruled out, usually through a separate blood test for 17-hydroxyprogesterone.
A much rarer cause of high DHEA-S is the presence of an adrenal tumor, which can be benign or cancerous. These tumors autonomously produce excessive amounts of adrenal hormones, including DHEA-S. This often leads to very high or rapidly rising levels substantially greater than those typically seen in PCOS. Such findings necessitate immediate imaging studies, like a CT or MRI, to visualize the adrenal glands and identify abnormal growths.
Cushing’s syndrome, characterized by prolonged exposure to high levels of cortisol, can also be associated with elevated DHEA levels. Furthermore, external factors such as DHEA supplements, chronic stress, or significant insulin resistance can contribute to increased DHEA-S production. A physician must consider all these possibilities to correctly determine the underlying cause of the hormonal imbalance.
The Process of Diagnosing PCOS
A high DHEA-S level is one piece of a larger diagnostic puzzle that requires a comprehensive approach to confirm PCOS. The most widely accepted framework for diagnosis is the Rotterdam criteria, which require a patient to exhibit at least two out of three specific findings. These criteria are hyperandrogenism (clinical or biochemical evidence of excess androgens), ovulatory dysfunction (irregular or absent menstrual cycles), and polycystic ovaries on ultrasound.
The diagnostic process begins with extensive blood work to assess hormone levels and exclude other conditions. Key tests include measuring total and free testosterone, as well as DHEA-S, to confirm hyperandrogenism. A check of 17-hydroxyprogesterone is performed to rule out NCCAH, and TSH and prolactin levels are checked to exclude thyroid or pituitary issues that mimic PCOS symptoms.
Ovulatory function is assessed by reviewing the patient’s menstrual cycle history. A pelvic ultrasound checks for the third criterion: the presence of polycystic ovaries. This is defined as having 12 or more small follicles (2 to 9 millimeters each) or an increased ovarian volume of over 10 milliliters. A definitive diagnosis of PCOS is made only when a patient meets two of these three criteria and all other possible causes of androgen excess and menstrual irregularity have been excluded.