For many women, nausea and vomiting are a normal part of early pregnancy. While often unpleasant, pregnancy sickness is usually manageable and tends to improve as pregnancy progresses, but for some women the symptoms become far more severe.
Hyperemesis Gravidarum (HG) is a serious pregnancy condition that causes severe nausea, persistent vomiting, dehydration, weight loss and an inability to carry out normal daily activities. It can be physically exhausting, emotionally overwhelming, and in some cases may require hospital treatment.
HG affects approximately 1 to 3% of pregnancies (approximately 30,000 in the UK) and is one of the most common reasons for hospital admission in early pregnancy.
Importantly, HG is not simply bad morning sickness, it is a recognised medical condition that deserves prompt assessment, treatment and compassionate support.
What Is Hyperemesis Gravidarum?
HG sits at the severe end of the pregnancy sickness spectrum. Women with HG often find even the simplest parts of daily life become difficult. Keeping food and fluids down can feel impossible, work may become unmanageable, and everyday tasks that would normally require little thought can suddenly feel overwhelming.
Many women find themselves spending much of the day simply trying to cope with the next wave of nausea. Symptoms can be present throughout the day and night, often with very little relief, and while some women begin to feel better as pregnancy progresses, others experience symptoms for much longer, with for 1 in 5 suffering until birth.
What Are the Symptoms?
Symptoms can vary, but often include:
- Severe and persistent nausea
- Frequent vomiting or retching
- Inability to tolerate food or fluids
- Dehydration
- Dizziness or fainting
- Weight loss
- Extreme fatigue
- Dark urine or reduced urine output
- Increased sensitivity to smells, light, noise, or movement
What Causes Hyperemesis Gravidarum?
For many years, the cause of HG was not well understood with women often told it was linked to stress or anxiety, but we now know this is not supported by evidence.
Research is increasingly pointing towards a hormone called GDF15, produced by the placenta and baby during pregnancy. This hormone acts on the part of the brain that controls nausea, vomiting, appetite and food aversion.
What seems to matter is not just the level of this hormone, but also how sensitive an individual woman is to it, which may help explain why some experience mild nausea, while others become severely unwell.
This is an important shift in understanding and moves HG away from outdated ideas about coping or mindset, and towards a clearer biological explanation. For many women, it also brings deep reassurance, knowing it is not caused by weakness, stress, anxiety, or an inability to cope, but a complex medical condition with real physical causes.
“Will this affect my baby?”
One of the most common concerns women share with me is whether their sickness is affecting their baby.
When you’re struggling to eat, drink, or keep anything down, it is completely understandable to worry that your baby isn’t getting what they need. The reassuring news is that in most cases, babies continue to grow and develop well, even when their mothers are experiencing significant sickness. Your body is remarkably good at prioritising your baby’s needs.
That doesn’t mean you should struggle on alone, however. Severe sickness can have a significant impact on your own health and wellbeing, which is why seeking help early is so important. With appropriate treatment, hydration, and support, most women go on to have healthy pregnancies and healthy babies.
If you are worried about your baby’s growth or wellbeing, speak to your midwife or maternity team. You should never feel you’re asking too many questions or seeking reassurance too often.
When should you seek help?
It is important to seek help early, rather than waiting for symptoms to become severe. You should contact your midwife, GP, maternity assessment unit, or NHS 111 if you are struggling to eat or drink, or if symptoms are affecting your ability to function day to day.
You do not need to reach a certain level of severity before asking for support, and if something doesn’t feel right, it is always appropriate to reach out.
Seek urgent advice if you are experiencing:
- Inability to keep fluids down
- Frequent vomiting throughout the day
- Signs of dehydration (very dark or minimal urine, dizziness, fainting)
- Significant or ongoing weight loss
- Severe weakness or exhaustion
- Blood in vomit
- Abdominal pain or fever
How Is HG treated?
If you are experiencing Hyperemesis Gravidarium, it is important to know help is available and you do not have to simply endure it.
Treatment will depend on the severity of your symptoms, but may include anti-sickness medication, fluids to treat dehydration, vitamin supplementation, nutritional support, and sometimes hospital admission if additional care is needed.
Many women worry about taking medication during pregnancy, but there are a number of treatments that can be used safely and effectively. In fact, treating HG early is often far safer than allowing dehydration, malnutrition, and ongoing weight loss to continue, and finding the right treatment can sometimes take time.
What works well for one woman may not work as effectively for another, and some women need a combination of medications before they begin to feel any improvement.
If a treatment is not helping or you feel your symptoms are worsening, please go back and seek further advice. You do not have to wait until you are at breaking point before asking for more support.
The aim is not simply to help you survive pregnancy, but to improve your quality of life and help you feel as well as possible during what can be an incredibly challenging time.
The emotional impact of HG
The emotional impact of HG is often underestimated, and when every day revolves around nausea, vomiting, and exhaustion, it can feel incredibly isolating.
Many women tell me they feel lonely, frightened, guilty, frustrated, and emotionally drained. Some feel guilty for not enjoying their pregnancy, while others grieve the experience they thought they would have.
It is entirely possible to feel grateful for your baby and still find pregnancy incredibly difficult. These feelings are not contradictory - they can exist side by side and both are valid.
Supporting someone with HG
Watching someone you love experience Hyperemesis Gravidarum can be incredibly difficult and is often hard to understand the impact of the condition unless you have experienced it yourself.
HG is far more than feeling sick. It can affect every aspect of daily life, leaving women physically exhausted, emotionally drained and struggling to do things they would normally take for granted.
One of the most valuable things you can offer is understanding. Believe what they are telling you, even if their symptoms seem difficult to imagine, and try not to minimise their experience or compare it to typical pregnancy sickness.
Practical support can make an enormous difference, so helping with meals, childcare, household tasks, shopping, or simply being present can ease some of the pressure when even the smallest jobs feel overwhelming.
Many women with HG also describe feeling isolated and misunderstood and sometimes, they do not need advice or solutions; they simply need someone to listen, acknowledge how difficult things are, and reassure them that they are not facing it alone.
You do not need to fix it or have all the answers, and often, knowing that someone believes them, supports them, and understands the seriousness of what they are experiencing can make a world of difference.
Where can you get help?
If you think you may have Hyperemesis Gravidarum, support is widely available. Please speak to:
- Your community midwife
- Your GP
- Your maternity assessment unit
- NHS 111 if you need urgent advice
You may also find helpful, evidence-based information through Pregnancy Sickness Support and the HER Foundation, both of which offer guidance and support for women affected by HG. You will also find general pregnancy health information via the NHS here.
Final Thoughts
Hyperemesis Gravidarum is far more than severe morning sickness, it is a serious pregnancy condition that can affect every aspect of physical and emotional wellbeing. As understanding continues to grow, we are moving away from outdated assumptions and towards a clearer, more compassionate understanding of what women are actually experiencing.
If you are going through this, I want you to know you are not alone, you are not imagining it and you deserve support. Please don’t hesitate in reaching out for help.
