Our Services | Department of Internal Medicine | UC Davis Health


Endocrinology, Diabetes and Metabolism

Our Services

Division of Endocrinology has 10 consultants Board Certified both in Internal Medicine and Endocrinology and Metabolism. As members of an academic institution, we apply the most recent advances to our practice. We also work very closely with our colleagues in surgery, otolaryngology, neurosurgery, bariatric surgery, nuclear medicine, radiology and pathology to provide comprehensive and coordinated care for our patients. Here, we offer a summary of the endocrine disorders we regularly take care of.

Endocrine Diseases

  • Congenital adrenal hyperplasia
  • Benign adrenal tumors
    • Incidentally discovered adrenal adenoma
    • Aldosteronoma
    • Cushing syndrome
    • Pheochromocytoma
  • Adrenal insufficiency
    • After steroid treatment
    • Addison's disease
  • Adrenal cancer

The most common adrenal problems referred to our care are adrenal tumors and adrenal insufficiency.  Adrenal tumors are usually discovered during a CT scan or a MRI performed for an unrelated reason.  While most of these tumors are benign, they can produce hormones which cause hypertension, lower potassium, and increase blood glucose, lead to obesity especially in the waistline.  Some of these may have potential of malignancy.  Therefore, proper endocrine work up and diagnosis are necessary.

The second common adrenal problem is adrenal insufficiency.  This condition can be caused by steroid treatment for various reasons such as lung disease or arthritis or even by steroid injections to joints.  On the other hand, many patients who complain of fatigue can be over diagnosed and mistreated with steroids.  Adrenal insufficiency is a serious condition and which should be diagnosed and treated by endocrine specialists.

  • Hyperparathyroidism
  • Hypercalcemia
  • Hypoparathyroidism
  • Hypocalcemia
  • Vitamin D deficiency
  • Osteoporosis
  • Osteopenia
  • Osteomalacia
  • Paget’s disease

The most common conditions we treat are osteoporosis, hyperparathyroidism and vitamin D deficiency.

Osteoporosis is generally treated very well by primary care physicians.  We deal with more complicated cases who cannot tolerate the first generation medications.  In addition, we give advice about when to stop the treatment and take a “drug holiday”.

Hyperparathyroidism and vitamin D deficiency can be complicated.  Hyperparathyroidism can be due to a tumor in the parathyroids which may need to be taken out by surgery.  On the other hand, vitamin D deficiency and kidney failure can activate the parathyroid glands, mimicking hyperparathyroidism.  Therefore, making the right diagnosis and avoiding unnecessary surgery are crucial.  In addition, certain precautions taken before surgery prevent complications after surgery.  It is always a good idea to be seen by an endocrinologist before deciding to have parathyroid surgery.

  • Hyperthyroidism
  • Graves’ disease
  • Thyroiditis
  • Hypothyroidism (underactive thyroid)
  • Hashimoto’s disease
  • Goiter
  • Thyroid nodule
    • Fine Needle Aspiration (FNA) of Thyroid
  • Thyroid cancer
    • Papillary thyroid cancer
    • Follicular thyroid cancer
    • Anaplastic Thyroid Cancer
    • Hurtle Cell Cancer

Thyroid disorders are very common.  Hypothyroidism is usually managed by the primary care physicians and we get involved only when there is a reason complicating the replacement.  The common reasons may be celiac disease, other medications interfering with absorption, hepatitis, other autoimmune diseases or estrogen treatment changing the binding protein for thyroid hormone.  Hypothyroidism caused by cardiac or anti-cancer medicines also requires consultation by endocrinologists.

Hyperthyroidism usually requires specialists care because it can be caused by Grave’s disease, thyroid nodule(s), silent subacute thyroiditis, iodine-contrast or drugs.  Management changes depending on the cause, patients’ age, reproductive plans, condition of the eyes (ophthalmopathy) and even smoking history.   Choice between medication, surgery or radioactive iodine therapy requires expert care.

Thyroid nodules are also very common.  Recent grading system of the ultrasound reporting triages the patients who require fine needle aspiration (FNA).  We routinely perform ultrasound assisted FNA in our clinic.  An advantage of having the FNA performed by an endocrinologist is that the physician who performs the FNA can follow up the patient.  When necessary she/he can arrange for additional work up (for example PET scan), surgery and subsequent nuclear medicine treatment.  If long-term care is needed, endocrinologist adjusts thyroid treatment dose, orders the blood tests and appropriate stimulation tests, ultrasounds and scans.  Establishing such life-long relationship with the endocrinologist assures successful management of thyroid cancer which has usually indolent, long-term course.

  • Pituitary tumors
    • Prolactinoma
    • Acromegaly
    • Cushing’s disease
  • Diabetes insipidus (DI)
  • Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
  • Sheehan’s syndrome

Pituitary disorders can be diagnosed earlier in younger women because they cause irregular periods or loss of periods.  However, in postmenopausal women and in men the majority of pituitary tumors are discovered incidentally during MRI or CT scan performed for an unrelated reason.   Pituitary tumors may cause a disease by over-producing hormones: For example, prolactin excess causes milk secretion from breasts and stops periods; growth hormone secretion enlarges hands and feet and causes diabetes; ACTH secretion causes Cushing’s disease with round face, purple stretch marks, weight gain to abdomen and raises blood sugars.  Alternatively, pituitary tumor may not produce a hormone but become very large and interferes with the secretion of other hormones from the pituitary.  Management of the tumor depends on the size and hormone secretion pattern.  Even if the tumor is treated with surgery, it is imperative to know if the remaining pituitary still has adequate function.  

Back portion of the pituitary gland regulates salt and water balance.  Patients who have deficiency of ADH (DI) urinate many liters during the day and constantly drink water.  Their blood sodium levels are very high.  This can be treated by taking ADH-pill or ADH-inhaler.  In contrast, patients who over produce ADH (SIADH) for different reasons can have very low sodium levels in the blood and suffer from confusion and even seizures.  Several diseases cause low or high sodium.  Accurate diagnosis of DI and SIADH require expert care.

  • Polycystic ovary syndrome (PCOS)
  • Menopause
  • Hirsutism (excess hair)
  • Alopecia (hair loss)
  • Galactorrhea (milky breast discharge)
  • Premature ovarian failure
  • Hypothalamic amenorrhea (loss of periods due to weight loss caused by eating disorders or excessive exercise)
  • Turner Syndrome
  • Fragile X syndrome

The most common female endocrine disorder we take care of is PCOS because PCOS affects one out of 10 young women and Dr. Karakas established a program in year 2000 to take care of PCOS patients.  This program receives referrals from all regions of California, Nevada and Oregon. Both endocrine and metabolic aspects of PCOS are addressed with the assistance of a Registered Dietitian/Certified Diabetes educator.  In addition, several off-label treatments benefit PCOS patients and it is important to be treated at a center informed about these tools.  Postmenopausal women who present with hirsutism (excess facial hair) and/or alopecia (hair loss in the scalp) are also taken care of at the PCOS program.

PCOS can co-exist with pituitary tumor producing prolactin (prolactinoma) or hypothalamic amenorrhea (loss of periods due to weight loss caused by eating disorders or excessive exercise).  Ovarian failure which occurs at a young age can be mistaken for PCOS.  Therefore it is important to make the accurate diagnosis using the state of the art diagnostic testing.  In the case of premature (early) ovarian failure, genetic testing, followed by genetic counseling, may be required.

  • Hypogonadism
  • Low testosterone
  • Gynecomastia
  • Klinefelter syndrome

The traditional age-related late onset hypogonadism can be treated by primary care physicians as long as the safety markers are monitored carefully.  However, many young men also suffer from low testosterone, low sperm count and other abnormal semen analysis findings.  The causes of these abnormalities can be testicular, hypothalamic/pituitary or medications such as opioids.  Specific work up to evaluate the defects in testosterone producing Leydig cells vs. sperm producing Sertoli cells may be needed.  Especially, young cancer survivors who have gone through chemotherapy and radiation are candidates for such evaluations.  Dr. Surampudi in our group has been trained in andrology and has the special skills to address these questions.

Metabolic Diseases

  • Type 1 diabetes
    • Insulin pump
    • Multiple insulin injection
    • Continuous glucose monitoring
  • Type 2 diabetes
    • Most current oral agents
    • Insulin therapy
    • GLP-1 therapy
    • Continuous glucose monitoring
  • Cystic fibrosis

Management of diabetes is changing on daily basis.  Availability of new insulin pumps and continuous glucose monitoring (CGM) devices is revolutionizing our practice.  For Type 2 diabetes, new GLP-1 analogs and SGLT-2 inhibitors are helping with weight management.  With the assistance of three Certified Diabetes Educators (two RN and one RD), we are able to offer these advances immediately to our patients.  We also work closely with our colleagues in nephrology and ophthalmology and have access to excellent vascular laboratories.  Hence we are able to offer state of the art, comprehensive, coordinated diabetes management.

Cystic Fibrosis (CF) related diabetes is a unique form of diabetes common in individuals with CF.  Dr. Yoon received an award from the Cystic Fibrosis (CF) Foundation to care for patients with CF related diabetes and works closely with colleagues in the Division of Pulmonology. He conducts research in CF related diabetes as well as the more common type 1 and type 2 diabetes.

Non-alcoholic fatty liver disease
Lipid disorders

  • High triglyceride
  • High LDL-cholesterol

We do not have a weight loss program for general obesity.  We accept limited number of patients with metabolic syndrome if they have complicated manifestation (for example, hypoglycemia confused with insulinoma; hypertriglyceridemia causing pancreatitis; metabolic syndrome accompanying PCOS).

Gender Affirming Care

The Gender-Affirming Care Clinic provides care for transgender, nonbinary, and gender-diverse individuals in a welcoming environment, where clinicians use an informed consent approach to starting and managing gender-affirming hormone therapy. The clinic can also assist with navigation and referrals for gender-affirming surgeries, and provide some sexual and reproductive health services. While this clinic is for adults, youth seeking gender-affirming care can be referred to the departments of Pediatric Endocrinology and Adolescent Medicine.