Endocrinology

Living with FHH1: Monitoring and the 'No-Surgery' Rule

At a Glance

The standard of care for Familial Hypocalciuric Hypercalcemia Type 1 (FHH1) is active observation, not parathyroid surgery. Because FHH1 is a genetic change to the body's calcium set-point, surgery is ineffective. Most patients live full lives with simple yearly monitoring of blood and bones.

For most patients with Familial Hypocalciuric Hypercalcemia Type 1 (FHH1), the most important “treatment” is actually no treatment at all ^[1]^[2]. Because FHH1 is a lifelong genetic trait where your body has simply chosen a higher “normal” for calcium, the standard of care is observation (regular monitoring) rather than active medical intervention ^[3]^[4].

Why Surgery is Not the Answer

In other conditions like Primary Hyperparathyroidism (PHPT), a small tumor on the parathyroid gland is the problem, and removing it is curative. FHH1 is different. It is a systemic “set-point” issue affecting every calcium-sensing cell in your body ^[5]^[3].

Because of this, parathyroid surgery (parathyroidectomy) is ineffective for FHH1 ^[6]^[7]. Studies show that about 83% of FHH1 patients who undergo surgery still have high calcium levels just one year later ^[6]. The remaining 17% do not represent “cures”; their calcium drops are usually temporary due to surgical shock or damage, eventually rising again ^[6]. Surgery does not fix the genetic “thermostat” and should be avoided to prevent unnecessary risks and recovery ^[8]^[9].

How to Monitor Your Health

While FHH1 is considered a benign condition (meaning it is generally stable, though it requires monitoring for specific complications over time), a small subset of patients may develop certain complications over many decades ^[3]^[10].

While you may not need active treatment, you should have a clear monitoring plan with your endocrinologist. A typical monitoring schedule might include:

Yearly Blood Work: To check your blood calcium, PTH, and kidney function (creatinine).
Bone Density (DEXA) Scans: To monitor for osteoporosis. While many FHH1 patients have healthy bones, some studies have noted a higher-than-average rate of bone fractures (14%) or osteoporosis (16%) in older adults ^[10].
Symptom Check-ins: Discuss any new joint pain, which can be a sign of chondrocalcinosis (calcium crystal deposits in the joints, found in about 22% of adult patients) ^[10]^[11]. You should also report any severe abdominal pain, as pancreatitis (inflammation of the pancreas) is a rare but documented risk ^[4]^[12].

When is Treatment Needed?

Medical treatment is rarely required, but it may be considered if a patient is severely symptomatic or develops specific complications, such as certain heart rhythm issues (like a short QT interval) ^[13]^[14].

The primary medications used are called calcimimetics (such as Cinacalcet) ^[15]^[16].

How they work: Think of these drugs as “glasses” for your calcium sensors. They bind to the CaSR protein and make it more sensitive to the calcium already in your blood ^[15]^[17].
The result: Once the sensors can “see” the calcium better, the parathyroid glands stop overproducing hormone, and blood calcium levels begin to drop toward a more typical range ^[18]^[14].

For the vast majority of people, however, simply knowing the diagnosis is enough. You can live a full, healthy life with FHH1 by simply monitoring your levels and ensuring that any future doctors understand that your “high” calcium is actually your body’s personal “normal” ^[3]^[19].

Return to the Home Page.

Common questions in this guide

Why is parathyroid surgery not recommended for FHH1?

Unlike other high calcium conditions caused by a tumor, FHH1 is a genetic trait affecting calcium sensors throughout your entire body. Surgery does not fix this genetic set-point, and most patients still have high calcium levels after the procedure.

What kind of monitoring is needed if I have FHH1?

Your endocrinologist will typically recommend yearly blood work to check your calcium, parathyroid hormone, and kidney function. You should also have periodic bone density scans and report any new joint or abdominal pain.

Are medications ever used to treat FHH1?

While rarely needed, medications called calcimimetics, such as Cinacalcet, can be prescribed if you develop severe symptoms or complications. These drugs help your body's calcium sensors better detect blood calcium, causing levels to drop toward a more typical range.

What are the long-term complications of FHH1?

FHH1 is generally benign, but some patients may develop complications over decades. These can include osteoporosis, calcium crystal deposits in the joints causing pain (chondrocalcinosis), or rarely, inflammation of the pancreas (pancreatitis).

Related questions

What Are the Long-Term Complications of FHH1? What Medications Are Used to Treat High Calcium in FHH1?

Get notified when new evidence is published on Familial hypocalciuric hypercalcemia type 1.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.

References (19)

1
Parathyroid hormone-dependent familial hypercalcemia with low measured PTH levels and a presumptive novel pathogenic mutation in CaSR.
Mahajan A, Buse J, Kline G
Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA 2020; (31(1)):203-207 doi:10.1007/s00198-019-05170-9.
PMID: 31641801
2
Familial hypocalciuric hypercalcemia in an infant: diagnosis and management quandaries.
Goldsweig B, Turk Yilmaz RS, Ravindranath Waikar A, et al.
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2024; (39(10)):1406-1411 doi:10.1093/jbmr/zjae137.
PMID: 39163488
3
Genetics of hereditary forms of primary hyperparathyroidism.
English KA, Lines KE, Thakker RV
Hormones (Athens, Greece) 2024; (23(1)):3-14 doi:10.1007/s42000-023-00508-9.
PMID: 38038882
4
Nephrotic Syndrome Complicated with Familial Hypocalciuric Hypercalcemia in an Infant: A Case Report and Comprehensive Literature Review.
Yu M, Xue M, Fan X, et al.
Alternative therapies in health and medicine 2024;.
PMID: 38702153
5
Rare diseases caused by abnormal calcium sensing and signalling.
Tőke J, Czirják G, Enyedi P, Tóth M
Endocrine 2021; (71(3)):611-617 doi:10.1007/s12020-021-02620-5.
PMID: 33528764
6
Novel mutations of the calcium-sensing receptor impede differential diagnosis of primary hyperparathyroidism and familial hypocalciuric hypercalcemia.
Bhangu JS, Baumgartner-Parzer S, Hargitai L, et al.
Gland surgery 2022; (11(1)):12-22 doi:10.21037/gs-21-577.
PMID: 35242665
7
Familial hypocalciuric hypercalcemia caused by homozygous CaSR gene mutation: A case report of a family.
Wang F, Hu J, Mei C, et al.
Medicine 2020; (99(35)):e21940 doi:10.1097/MD.0000000000021940.
PMID: 32871939
8
A case of familial hypocalciuric hypercalcemia type 1 due to CASR p.Pro55Leu mutation.
Sumida A, Iizuka K, Kato T, et al.
BMC endocrine disorders 2022; (22(1)):164 doi:10.1186/s12902-022-01077-5.
PMID: 35733207
9
Multiple endocrine neoplasia phenocopy revealed as a co-occurring neuroendocrine tumor and familial hypocalciuric hypercalcemia type 3.
Hovden S, Jespersen ML, Nissen PH, et al.
Clinical case reports 2016; (4(10)):922-927 doi:10.1002/ccr3.657.
PMID: 27761240
10
Clinical characteristics of familial hypocalciuric hypercalcaemia type 1: A multicentre study of 77 adult patients.
Mouly C, Vargas-Poussou R, Lienhardt A, et al.
Clinical endocrinology 2020; (93(3)):248-260 doi:10.1111/cen.14211.
PMID: 32347971
11
Case Report: Familial hypocalciuric hypercalcemia type 1 with a novel mutation combined with Gitelman syndrome and a review of the literature.
He T, Li X, Li G, et al.
Frontiers in endocrinology 2025; (16()):1503128 doi:10.3389/fendo.2025.1503128.
PMID: 40070587
12
A Rare Case of Familial Hypocalciuric Hypercalcemia in Patient With Pancreatitis.
Khan MI, Jain T, Abid MM, et al.
Journal of community hospital internal medicine perspectives 2025; (15(4)):66-68 doi:10.55729/2000-9666.1497.
PMID: 40757212
13
Successful use of cinacalcet to treat parathyroid-related hypercalcemia in two pediatric patients.
Mogas E, Campos-Martorell A, Clemente M, et al.
Endocrinology, diabetes & metabolism case reports 2018; (2018()).
PMID: 29899992
14
Cinacalcet Reverses Short QT Interval in Familial Hypocalciuric Hypercalcemia Type 1.
Cuny T, Romanet P, Goldsworthy M, et al.
The Journal of clinical endocrinology and metabolism 2024; (109(2)):549-556 doi:10.1210/clinem/dgad494.
PMID: 37602721
15
[Pharmacological characteristics of drugs targeted on calcium-sensing receptor.-properties of cinacalcet hydrochloride as allosteric modulator].
Nagano N, Tsutsui T
Clinical calcium 2016; (26(6)):839-50.
PMID: 27230839
16
Cinacalcet corrects biased allosteric modulation of CaSR by AHH autoantibody.
Makita N, Ando T, Sato J, et al.
JCI insight 2019; (4(8)).
PMID: 30996138
17
Allosteric modulation and G-protein selectivity of the Ca2+-sensing receptor.
He F, Wu CG, Gao Y, et al.
Nature 2024; (626(8001)):1141-1148 doi:10.1038/s41586-024-07055-2.
PMID: 38326620
18
Familial hypocalciuric hypercalcemia and related disorders.
Lee JY, Shoback DM
Best practice & research. Clinical endocrinology & metabolism 2018; (32(5)):609-619 doi:10.1016/j.beem.2018.05.004.
PMID: 30449544
19
Severe Symptomatic Hypercalcemia in a Patient With Familial Hypocalciuric Hypercalcemia.
Kurian R, Madegowda Chandrashekar G, Antony MA, et al.
Cureus 2021; (13(11)):e20057 doi:10.7759/cureus.20057.
PMID: 34993031

This page explains FHH1 management and monitoring for educational purposes only. Always consult your endocrinologist regarding your specific condition and before making any changes to your care plan.