Hypos: tighter control & its impact
Fitting tighter control into your lifestyle
- Remember that you are an important member of your diabetes care team
- you will have a better chance of success if you all work together as
a team. You may need extra support and advice from your diabetes care
team on how to maintain good control.
- Your current level of control will be based on your HbA1c
level. This is an average of your blood glucose levels over the
last 6-10 weeks. Try to improve your lifestyle generally. Focus on healthy eating and
regular exercise. Decide what is best for you with your doctor.
- In the DCCT,
people in the intensive group gained an average of 10 lbs. more than
those in the standard group, but your dietician and he DAFNE program (type 1 patients) will be able to
advise you about healthy eating.
- Keep records of your activities, the food you
eat, your blood glucose levels and the amount of insulin you inject.
These records will enable you and your diabetes care team.
- Be honest with yourself and your diabetes care team. For instance, tell
your doctor if you know that you won't take exercise, otherwise you will
set yourself up for failure from the start.
- Be prepared to experiment with your control while you learn what is
best for you don't expect to achieve good control from the word go; changes
always take time.
- Remember that with tight control hypos can happen very fast meaning
that you may not always have time to test your blood. Be aware of the
warning signs such as sweaty hands, increased heart rate and shakiness.
Tell your doctor if you are not experiencing warning signs, especially
if your insulin dose has been changed recently.
- If you have tightened up your control, remember to test your blood glucose
level before you drive - low blood glucose when driving could cause an
- Be prepared for hypos by making sure that you always have some glucose
- Tell your family and friends what you are doing - they won't be able
to support you if they don't understand why you are monitoring, for example,
and what the information means.
- Expect to have hard days as well as good days - getting through will
make success at the end seem even better!
- A hypo is defined for patients as a sugar less than 3.6 mmol/l. However,
technically you do not get symptoms with a sugar below 3.5mmol/l, and
you may not need to take corrective action unless your sugar is
<3.5mmol/l, but particularly <3.0mmol/l.
- Only half of patients tell their doctor they have had a serious hypo.
Why do hypos happen?
- too much insulin
- inappropriate insulin regimens (incorrect doses and insulin types)
- injection site problems
- too little food
- more exercise than usual
- this may cause a hypo in the night or the next morning after exercise the day before
- consider having a complex carbohydrate if going out drinking (eg crisps or a snack)
- it delays gluconeogenesis
- less commonly, other illness such as coeliac disease, thyroid, addisons, gastroparesis (digestion problems), psychological problems
- changes in insulin sensitivity (including drugs affecting
the renin-angiotensin system and renal failure)
- they are much commoner if patients have renal problems having had diabetes for many years.
Impact of Hypoglycaemia: modified from
Dr Stephanie Amiel
Hypoglycaemia (low blood glucose) occurs whenever there is more insulin
in the body than is needed. It is usually uncomfortable rather than dangerous,
but occasionally blood glucose goes so low that the brain runs out of fuel
and ceases to work properly. Confusion, irritability, even unconsciousness,
A severe hypo leaves the person with diabetes unable to help themselves and needing help from someone else. This unpleasant, embarrassing and potentially
dangerous complication of insulin treatment is not very common. However,
those people on intensive insulin treatment are at greater risk. Why?
Hypo warning symptoms
|Hypo warning symptoms
- shaky, tremors
- very hungry
- anger, irritation
- running away
- laughing, silliness
- high stress/emotions
- an early morning headache like a hangover
Usually, your body recognises a small fall in blood glucose and tells you
about it long before you have any confusion or inability to cope. Early warning
symptoms of hypos include feeling sweaty, shaky, hot, cold, anxious, very
hungry or drowsy. You may also lose your concentration, have difficulty speaking
and become irritable.
When you feel these symptoms, you should (ideally!) check your blood glucose
and if it is low, correct it by eating something rich in carbohydrate immediately.
You are only at risk of greater confusion and perhaps loss of consciousness
if your blood glucose continues to fall.
Losing your hypo warning signs... 'hypo-unawareness'
Some people lose their early warning symptoms of hypoglycaemia. About a
quarter of all people who have had diabetes for a long duration (say more
than 15 years), find their hypo symptoms have changed so much that they may
miss them altogether. But loss of warning of a hypo does also seem to be
more common in people using intensive insulin treatment and may contribute
to the increased risk of severe hypos.
This is partly because there is less leeway with tight diabetes control;
if your background blood glucose is nearly normal, a small drop in blood
glucose, perhaps from unexpected exertion or a late snack, may take you really
low. As a result, you may be too confused by the time the symptoms arrive
to recognise them for what they are. See case
A common reason for having too many hypos that you are not aware of is that
you are simply having too many, and your body cannot cope, wearing out (temporarily)
the body's warning system. The repeated undetected periods of hypos (<3.5
mmol/l) often for extended periods, commonly at night.
When hypos are serious are frequent, review possible contributory causes
- inappropriate insulin regimens (incorrect dose distributions and insulin
- meal and activity patterns, including alcohol
- injection technique and skills, including insulin resuspension
- injection site problems
- possible organic causes including gastroparesis
- psychological problems
- previous physical activity
- lack of appropriate knowledge and skills for self management
- changes in insulin sensitivity (including blood pressure drugs and renal
- psychological problems
- previous physical activity
- lack of knowledge about self-management
This review needs to be carried out with the help of your diabetes nurse
/doctor. If the cause is unclear, and glucose monitor may help. These can
monitor glucose levels overnight, and l can tell your nurses when your hypos
Who is at risk?
Hypos are slightly more common at night. About half of the daytime episodes
apparently occurred without proper warning symptoms. Severe hypos are more
common with intensive insulin treatment....for every 1% lowering of glycated haemoglobin
(HbA1c), there is a 36% increase in risk (DCCT).
A hypo can occur at high glucose levels. If a person normally has a glucose level of 15mmol/l, then even a drop to 10 can cause a hypo. Commonly, if the glucose is normally 9, then a level of 5 may cause a hypo.
However, the most serious hypos occur at much lower glucose levels. So if a person is very well controlled, with normal glucose levels of 5-6mmol/l, the such a patients will occur is levels drop to 2 or less (and at this level the hypos may be severe with unconsciousness)
So should I improve my diabetes control?
Generally the risk of hypos should not stop you trying to improve your control.
We have learnt a lot about hypos and what contributes to the risk of having
severe ones. In the DCCT itself, the frequency of severe hypos declined as
time went on and people started to understand the causes of severe hypos.
When is tight control not advisable?
People on tight control in the DCCT who
experienced more hypos said that hypos did not affect their quality of life.
But there are some groups of people who should be wary of keeping their blood
glucose levels too tightly controlled because of potential hazards should
severe hypos occur. They include:
- children under the age of seven years
- the elderly
- possibly some people living alone
- people who have lost their hypo warning signs
There is no proven advantage either for people who already have advanced
complications such as severe visual loss or kidney failure (though there
were no such people in the DCCT).
Defining your 'lower limit'
Including a lower limit in definitions of 'good' diabetes control is very
The DCCT researchers
decided that very low blood glucose levels (around 3-4 mmol/l) were something
to be avoided and that blood glucose should be kept above 3.6 mmol/l in the
middle of the night. Research studies have shown that eliminating hypoglycaemia
from daily life may even restore warning symptoms of the occasional hypo
that may creep in!
How do I avoid too many hypos?
Think about (and check) your blood glucose readings when you think you might
be most at risk.
- Hypos at night may not produce symptoms but may be enough to cause loss
of awareness to day time hypos too.
- Vigorous exercise in the day may increase the risk of hypoglycaemia during
- The time between meals is another thing to watch. If your glucose levels
are normal immediately after a meal, you may well hypo before the next
meal if you exercise or miss your snack.
- Remember too that blood glucose levels of less than 3.5 mmol/l do not
occur in people who do not have diabetes. If you see several of these low
values when you check your blood glucose at home, try and adjust your regimen
so that they don't happen in the future. Your clinic will help you. See
also testing your sugar
Alcohol increases susceptibility to hypos as it affects glucose metabolism
and reduces the warning signs. Binge drinking is dangerous in diabetes, but
if you 'have to' binge drink, maintain higher than usual glucose levels,
and test your glucose levels more often, especially in the night after the
Discussed in more detail here. If
you play a round of golf for instance, to prevent a hypo you should reduce
the dose of the previous insulin injection, both short and long acting types.
If you forgot to do this, or did not have chance to plan ahead, expect a
hypo: test your sugar before and half way round if you get the chance, but
if not have something extra to eat before you start, and half way round.
Test when you finish, as you may need something to eat then as well.
If you have a lot of vigorous exercise during
the day, you need a lot less insulin (a
30-50% reduction may be needed). If you do not have chance to reduce
your insulin both in advance and after the exercise, you may get a hypo in
the evening or even in the night. So reduce your insulin, and eat more, and
test often. (Even in the evening after the vigorous exercise.)
Eventually you will learn how to make the adjustments and have very few
hypos, but it takes a lot of practice and testing, and advice from you diabetic
nurse. Try and increase your exercise gradually to avoid this. If you exercise
at weekends only, and have a desk job during the week,remember you will need
vastly different insulin doses at the weekends. With planning, testing, and
adjusting doses, good control is still achievable.
As mentioned, when you have an infection your sugar goes up and you need
more insulin. When the infection goes you will have to reduce your insulin,
so be prepared, test, adjust, and look out for a hypo.
Prepare for hypos
If you are driving, always have a few cartons of orange juice with you.
A salad sandwich or fruit would be useful as well, reserving sweets as a
last resort. If you are changing your insulin regime, have taken more exercise
than usual, or feel sick, a hypos may be more likely. Generally insulin users
should test their sugar level before starting to drive and every 90 minutes.
- BMJ 16
- before exercise blood glucose 7-12 mmol/l
- ?extra carbohydrate if <7 mmol/l before exercise
- measure glucose before, during , and after exercise
- consider 20% reduction of insulin dose, before moderate intensity during exercise, as well as fast acting carbohydrate during the exercise. (general guide 1g/kg/hour)
- Blood Glucose Awareness training should be available from your local diabetes clinic USA USA
What to do if you get a hypo
Hypo treatment.... lucozade, carton orange juice, dextrose tablet, followed by complex carbohydrate such a a bandana or sandwich.
Naturally this depends on the hypo, and it is better to try and predict
one and take preventative action. In practice many people with diabetes do
notice occasional hypos, even if they try really hard to avoid them. If you
think you are getting hypos regularly YOU MUST TEST YOUR SUGAR to confirm
they are hypos if you are to have any chance of controlling your diabetes
- link how to treat a hypo
- if you think you might be getting one, test your sugar if you can. If
you cannot test, and particularly if you are driving, you will need to
drink or eat
- BMJ 16 15g of fast acting carbohydrate such as a sugary drink, or 3 'jelly babies', or 30g/100kg body weight
- a small carton of orange juice has enough sugar in to make your sugar
rise; this might be enough for a mild hypo. Dextrosol tablets in the car can be helpful. Chocolates or sweets will get eaten before the hypo!
- after the orange juice has caused the immediate rise, a salad sandwich
or banana will help to produce a more sustained rise in sugar
- in unusual situations, such as taking far more insulin than you needed,
or having a lot more exercise than you are accosted to, even this will
not be enough, and you may need more food
- in an emergency small amounts of sugary food help
- A whole mars bar though
contains enough sugar to destabilise your diabetes for days. A small
sweet or half a mini-mars bar followed by a fruit or sandwich would be
- if you are unconscious a carer can give you a glucagon injection,
and when you wake up, you need a drink and some food. This is a very
serious situation, an expert advice is needed, and sometimes an emergency
paramedic will be needed.
- measure glucose level 10 minutes after glucagon
- if still unconscious intravenous glucose is needed
- the give oral carbohydrate
- Milder hypos: 3 dextrose tablets may suffice, probably followed by more complex carbohydrate
such as a sandwich or banana. Chocolate and biscuits are not ideal (but
may work in an emergency).
A glucagon injection can be injected by someone else if you have a severe
hypo, although you need a sugary drink afterwards. Intramuscular glucagon
(0.5-1mg...the higher dose may produce vomiting particularly in children).
It is not effective in alcoholics. After recovery, have some oral carbohydrate,
such as a sugary drink or orange juice, followed by a sandwich or some other
carbohydrate. There should be a response in 10 minutes (otherwise intravenous
glucose is needed.)
This website cannot advise relatives when to call a paramedic, but if you
are not sure what is going on, it is best to call for urgent paramedic help.
After recovery from the glucagon you need to contact your nurse/doctor for advice.
Treatment of hypo-unawareness/frequent hypos
- You will need expert help from your nurse and doctor
- The newer insulin regimes which are based on Glargine or detemir are
likely to be very helpful, especially in reducing night time hypos.
- Night time hypos..make sure you are using the newer Glargine or detemir
- If your hypo is related to exercise, clearly you have not adjusted your
insulin enough..you needed less insulin before the hypo
- For frequent hypos that you are not aware of, try and reduce your insulin,
all doses, for 4-6 weeks (with expert help). Gradually your hypo symptoms
should return, and then you can start to very gradually increase your
insulin doses, with expert help.
- Some people say they get hypos at higher levels of 6 or 8. Generally
expert help is needed, but in practice it is very usual to get a 'hypo'
at a level of 8...you may be noticing another problem.
- Autonomic neuropathy is a cause on unawareness. Nevertheless with care
some awareness may be restored. See and
and more and here.
- Whilst seeking help for your doctor and nurse, if you think insulin
is the cause:
- reduce most of your insulin doses 2-4 units
- test frequently, 6 times a day
- your tests should then reveal no hypos, otherwise you may have to
reduce your insulin more
- when your body adjusts to the higher sugar levels, perhaps in a
2 weeks or so, you should start to recognise hypos again. You need
to keep testing your sugar levels.
- Gradually increase your insulin levels so that your sugar reaches
reasonably low levels, but not the very low hypo levels you had before.
- Primary care teams are not expert enough at tackling such problems BMJ
- If the diabetes is well controlled, then hypos might be more severe as the glucose level will be lower (affecting the brain more). Poorer controlled patients get hypos at a higher glucose level.
- Hypo unawareness may be reduced with a islet cell transplant. Hypo unawareness after 30y of diabetes might be impossible to remedy.
- Hypos occur often at night. They seem particularly common post-pregnancy, when a women wants good control, but the control may be too 'good'.
Treatment of hypos at night
Hypos at night may be noticed by patients or detected by implantable monitors
(available for a few days from hospital diabetic clinics) should be managed
- reviewing current insulin regimes, evening eating habits, and previous
- choosing an insulin type and regimen less likely to cause a low glucose
levels in at night, such as:
- rapid-acting analogue with the evening meal
- long-acting insulin analogues Lantus/Glargine & Levemir/detemir
- insulin pumps
What if you have had bad hypos recently and are afraid of trying to lower
your average blood glucose level? Suppose you've dealt with the problem by
relaxing your diabetes control until your blood glucose are always high
(say over 9 mmol/l) and you've stopped the hypos but now have a high HbA1c
with its increased risk of long term diabetes complications.
Remember that the risk of diabetes complications is almost directly related
to the value of the glycated haemoglobin (HbA1c) and almost any reduction
In average blood glucose and HbA1c will now be useful.
Don't give up just because you despair of perfection - it is worth lowering
your HbA1c as much as you can without starting to hypo again. And
look very carefully at the spread of your home blood glucose readings -getting
rid of those under 4 mmol/l readings may be all you have to do!
We now know that the better your blood glucose control over the years,
the better your chances of avoiding diabetic complications. And we also know
that really good control means avoiding hypos too --both the severe and mild
ones. Visit the AIDA computer
model of insulin/sugar levels.
- No driving if more than 1 severe hypo in one year (must notify the DVLA).
- If using drugs that can cause hypos (insulin particularly), test glucose before driving and every 2 hours driving, keep the results on a meter. The meter and its results will be examined by the police if there is an accident. The meter must keep results for the weeks before also (for the police if needed).
- links, very helpful driving with diabetes driving for work driving and hypoglycaemia