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PubMed This is a summary of 18 peer-reviewed journal articles Updated
Pediatric Nephrology

Symptoms and Warning Signs to Watch For

At a Glance

Congenital renal artery stenosis can cause dangerously high blood pressure in children without obvious symptoms. Babies may have feeding or breathing problems, while older children may have headaches or vision changes; seizures, breathing distress, or severe vision loss require emergency care.

Congenital Renal Artery Stenosis (CRAS) is often called a “silent” condition because children may not feel or look sick even when their blood pressure is dangerously high [1][2]. Because children cannot always tell you how they feel, recognizing the subtle signs and understanding the rare but serious complications is vital for managing their health.

How Symptoms Differ by Age

The way high blood pressure (hypertension) appears depends heavily on a child’s age.

Infants and Toddlers

In the youngest patients, symptoms are often non-specific and can be mistaken for other common childhood issues.

  • Heart Failure Signs: Because the heart must pump against much higher pressure, it can become overstressed. Signs include fast or labored breathing (tachypnea), sweating during feedings, or becoming too tired to finish a bottle [3][4].
  • Failure to Thrive: A baby may not gain weight at the expected rate or may even lose weight because their body is struggling to manage the high pressure [4].
  • Behavioral Changes: Extreme irritability or a baby who is unusually difficult to soothe can sometimes be a sign of the physical stress caused by hypertension [4].

Older Children and Adolescents

As children grow, they may be able to describe symptoms more clearly, though up to half of children with very high blood pressure may still have no symptoms at all [1].

  • Headaches and Vomiting: Persistent, severe headaches or unexplained vomiting can be a sign that high blood pressure is affecting the brain [1][5].
  • Vision Changes: High pressure can damage the small blood vessels in the back of the eye, leading to blurry vision or other visual disturbances [1][6].
  • Abdominal Bruit: A doctor may hear a “whooshing” sound (a bruit) when listening to your child’s belly with a stethoscope, which is the sound of blood passing through a narrowed artery [2].

Understanding Hyponatremic Hypertensive Syndrome (HHS)

Hyponatremic Hypertensive Syndrome (HHS) is a rare but serious complication specifically linked to renal artery narrowing [7]. In this condition, the “starved” kidney releases so much renin that the other (healthy) kidney begins to dump massive amounts of salt and water into the urine [8][9].

This creates a dangerous paradox: the child has very high blood pressure but is also severely dehydrated and low on essential salts like sodium (hyponatremia) [7][10]. Signs of HHS include:

  • Extreme thirst (polydipsia) and excessive urination (polyuria) [7].
  • Rapid, unexplained weight loss [7].
  • Vomiting and significant lethargy [10].

Red Flags: When to Seek Emergency Care

In the context of CRAS, a “hypertensive emergency” is defined not just by the blood pressure number, but by whether that pressure is causing immediate damage to the brain, heart, eyes, or kidneys [11][12].

Seek emergency medical attention immediately if your child experiences any of the following:

  • Neurological Changes: New seizures, confusion, extreme sleepiness, or a sudden change in how they walk or talk [13][14].
  • Respiratory Distress: Sudden shortness of breath, a blue tint to the lips, or a sudden inability to breathe comfortably while lying flat [3].
  • Severe Vision Loss: Sudden or rapidly worsening blurry vision [15].
  • Refractory Symptoms: High blood pressure that remains at dangerous levels despite taking all prescribed rescue medications, especially if accompanied by the “HHS” signs of extreme thirst and weight loss [7][16].

If Your Child’s Blood Pressure is High:

  • A single high blood pressure reading in a child who is eating and breathing normally still requires a careful response. Repeat the reading after appropriate rest with a validated, correctly sized cuff [17].
  • Contact your pediatric nephrologist promptly for clinician-defined severe readings, even if the child appears well [18].
  • Mild headaches that resolve with rest and are not associated with vomiting or vision changes should always be reported to your care team [1].

Common questions in this guide

Can a child have congenital renal artery stenosis without obvious symptoms?
Yes. Children with congenital renal artery stenosis may have dangerously high blood pressure yet appear well, and some children have no symptoms even when the pressure is very high. Regular blood pressure checks and guidance from the child’s clinician are important.
What signs might a baby with CRAS show during feeding?
A baby may breathe quickly or work hard to breathe, sweat during feeds, tire before finishing a bottle, gain weight slowly, or become unusually irritable. These signs can have many causes, so prompt discussion with the child’s clinician is important.
What symptoms of high blood pressure should I watch for in an older child?
Persistent or severe headaches, unexplained vomiting, and blurred vision can occur when high blood pressure affects an older child. A clinician may also hear a whooshing sound over the abdomen caused by blood moving through a narrowed artery.
What could extreme thirst and frequent urination mean in a child with CRAS?
Extreme thirst and frequent urination can be signs of hyponatremic hypertensive syndrome, a rare but serious complication of renal artery narrowing. Rapid weight loss, vomiting, or unusual sleepiness or weakness alongside these symptoms needs prompt medical evaluation.
Which symptoms mean my child needs emergency care?
Seek emergency help for new seizures, confusion, extreme sleepiness, sudden changes in walking or speech, breathing distress, blue lips, or sudden severe vision loss. Blood pressure that stays dangerously high despite prescribed rescue medication, especially with extreme thirst or weight loss, also requires urgent care.
What should I do after one high blood pressure reading?
Let your child rest and repeat the reading with a validated monitor and a correctly sized cuff, unless emergency symptoms are present. Contact the pediatric nephrology team promptly for clinician-defined severe readings even if your child appears well.
What should I do about my child’s blood pressure medicine if they are vomiting or dehydrated?
Ask the prescribing clinician promptly for individualized instructions before changing or stopping blood pressure medicine during vomiting or dehydration. Follow the child’s emergency plan and seek urgent care if severe symptoms or dangerous blood pressure occur.

Questions For You

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Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does my child have any signs of heart failure or an enlarged heart on their echocardiogram?
  2. 2.Based on my child's age and height, what is the exact blood pressure number that would be considered a hypertensive emergency?
  3. 3.Could my child's thirst and frequent urination be a sign of hyponatremic hypertensive syndrome?
  4. 4.How should we monitor my child for signs of organ damage in their eyes or kidneys?
  5. 5.Is it safe to continue our current blood pressure medication if my child develops a stomach bug or becomes dehydrated?

References

References (18)
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    Hypertension crisis as the first symptom of renovascular hypertension in children.

    Xu L, Ba H, Jiang X, Qin Y

    Italian journal of pediatrics 2022; (48(1)):191 doi:10.1186/s13052-022-01378-4.

    PMID: 36461036
  2. 2

    Renovascular hypertension in pediatric patients: update on diagnosis and management.

    de Oliveira Campos JL, Bitencourt L, Pedrosa AL, et al.

    Pediatric nephrology (Berlin, Germany) 2021; (36(12)):3853-3868 doi:10.1007/s00467-021-05063-2.

    PMID: 33851262
  3. 3

    Presentation, treatment, and outcome of renovascular hypertension below 2 years of age.

    Kurt-Sukur ED, Brennan E, Davis M, et al.

    European journal of pediatrics 2022; (181(9)):3367-3375 doi:10.1007/s00431-022-04550-4.

    PMID: 35792951
  4. 4

    Renovascular hypertension: a case with atypical neurological signs.

    Jerónimo M, Dionísio T, Gomes C, Neves JF

    BMJ case reports 2015; (2015()).

    PMID: 26351310
  5. 5

    Severe arterial hypertension, a silent complication of Williams-Beuren syndrome: A case report with literature review.

    Tizki S, Ouafik I, Azzouzi FZ, et al.

    Radiology case reports 2026; (21(11)):5372-5379 doi:10.1016/j.radcr.2026.07.058.

    PMID: 42633204
  6. 6

    Pediatric renovascular hypertension: Treatment outcome according to underlying disease.

    Lee Y, Lim YS, Lee ST, Cho H

    Pediatrics international : official journal of the Japan Pediatric Society 2018; (60(3)):264-269 doi:10.1111/ped.13491.

    PMID: 29281158
  7. 7

    Multimodal imaging approach in hyponatremic hypertensive syndrome. A rare case of pediatric unilateral hypoplasia of the main renal artery combined itself with stenosis and review of literature.

    Siervo A, Castaldo A, Furlan D, et al.

    Radiology case reports 2023; (18(3)):869-877 doi:10.1016/j.radcr.2022.10.034.

    PMID: 36589503
  8. 8

    Fetal congenital midaortic syndrome with unilateral renal artery stenosis prenatally presenting with polyhydramnios and postpartum as hyponatremic hypertensive syndrome.

    Ardabili S, Uerlings V, Kaelin Agten A, Hodel M

    BMJ case reports 2020; (13(5)) doi:10.1136/bcr-2020-234459.

    PMID: 32444441
  9. 9

    Unilateral renal artery stenosis presented with hyponatremic-hypertensive syndrome - case report and literature review.

    Ding JJ, Lin SH, Lai JY, et al.

    BMC nephrology 2019; (20(1)):64 doi:10.1186/s12882-019-1246-9.

    PMID: 30791890
  10. 10

    Hyponatremic-hypertensive Syndrome in a 19-month-old Boy with Renovascular Hypertension.

    Kara MA, Kilic BD, Karakus SC, et al.

    Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia 2022; (33(Supplement)):S87-S90 doi:10.4103/1319-2442.374386.

    PMID: 37102529
  11. 11

    Hypertensive crisis in children and adolescents.

    Seeman T, Hamdani G, Mitsnefes M

    Pediatric nephrology (Berlin, Germany) 2019; (34(12)):2523-2537 doi:10.1007/s00467-018-4092-2.

    PMID: 30276533
  12. 12

    Hypertensive crisis in children: an experience in a single tertiary care center in Korea.

    Lee GH, Lee IR, Park SJ, et al.

    Clinical hypertension 2015; (22()):10 doi:10.1186/s40885-016-0040-2.

    PMID: 27092268
  13. 13

    Renal artery stenosis precipitates hyponatremic hypertensive syndrome and posterior reversible leukoencephalopathy.

    Parikh P, Duhame D, Monahan L, Woroniecki R

    Frontiers in pediatrics 2015; (3()):40 doi:10.3389/fped.2015.00040.

    PMID: 26000267
  14. 14

    Hyponatremic hypertensive syndrome - a retrospective cohort study.

    Mukherjee D, Sinha R, Akhtar MS, Saha AS

    World journal of nephrology 2017; (6(1)):41-44 doi:10.5527/wjn.v6.i1.41.

    PMID: 28101450
  15. 15

    Clinical Characteristics of Hospitalized Pediatric Patients With Hypertensive Crisis-A Retrospective, Single-Center Study in China.

    Ba H, Peng H, Xu L, et al.

    Frontiers in cardiovascular medicine 2022; (9()):891804 doi:10.3389/fcvm.2022.891804.

    PMID: 35711370
  16. 16

    Efficacy of Antihypertensive Therapy in a Child with Unilateral Focal Fibromuscular Dysplasia of the Renal Artery: A Case Study and Review of Literature.

    Acharya R, Ellenwood S, Upadhyay K

    Medicines (Basel, Switzerland) 2020; (7(2)) doi:10.3390/medicines7020009.

    PMID: 32093171
  17. 17

    Paediatric midaortic syndrome associated with ascending aortic and renal aneurysm managed with complex multidisciplinary medical management and surgical repair.

    Singh ES, Williams A, Weissler EH, Coleman DM

    BMJ case reports 2026; (19(8)) doi:10.1136/bcr-2025-266584.

    PMID: 42562451
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    Hypertensive Crisis in Pediatric Patients: An Overview.

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    PMID: 33194923

This page is for informational purposes only and does not constitute medical advice. It describes warning signs in children with congenital renal artery stenosis; contact your child’s pediatric nephrology team or emergency services when urgent symptoms occur.