You're probably familiar with the idea that the symptoms of ADHD are actually due to an ADHD comorbid disorder or a different, undiagnosed problem.
One such health condition that may be responsible for your child's hyperactive behavior is a sensory motor disorder called restless leg syndrome (RLS).
RLS is characterized by a discomfort in the legs that requires motion to provide temporary relief.
These motions might include repetitive jerks, hyperactive behavior, and fidgeting in one's seat.
RLS may also cause short attention spans, mood swings, and lethargy due to its tendency to interrupt sleep What causes RLS? The cause behind restless leg syndrome provides compelling evidence for its postulated relationship with ADHD.
RLS is actually a problem of the central nervous system rather than the musculoskeletal condition; it has been found to be related to an insufficient amount of dopamine in the brain.
Dopamine is the neurotransmitter that controls movement.
Dopamine levels naturally fall as it gets dark, which can explain why your child tends to be more hyperactive late in the afternoon or during night time.
RLS was also found to be related to low iron stores; iron is critical to the production of dopamine.
Symptoms of RLS The most common symptoms of RLS bear a striking resemblance to the hyperactive component of ADHD:

• Irritating sensations - children with RLS feel discomfort in their legs, feet, hands, or arms
• Hyperactivity and restlessness - moving around or fidgeting relieves the discomfort
• Getting worse during night - the hyperactive behavior gets worse at night because the irritating sensations increase
• Restlessness triggered by staying still - your child's toes, feet, hands, or fingers might jerk or move slightly when he or she is at rest
• Insomnia - the need to relieve the discomfort in the affected limbs might cause insomnia or disrupted sleep

Diagnosing and treating RLS Just like ADHD, there is no single test that can detect restless leg syndrome; it's not uncommon for the condition to go undiagnosed until the child has reached adulthood.
However, a doctor can make a diagnosis based on certain criteria and a full evaluation.
Restless leg syndrome can be treated by stimulant drug,s but if you'd rather not place your child on medications, there are ways to treat it naturally:

• Provide iron supplements.
  Get your child tested for low iron levels.
  If the test turns out positive, provide iron supplements to boost the production of dopamine.
  
• Eliminate soda and other caffeinated drinks.
  Caffeine and other stimulants often aggravate symptoms of RLS, especially at night.
  
• At night, wrap legs or feet in bandages.
  
• Exercise.
  Exercises that strengthen the legs, feet, hands, and arms can diminish RLS symptoms.
  A regular walking program was also found to be helpful.
  
• Neuromuscular massage.
  Receiving regular neuromuscular massage therapy on the affected limbs was found to reduce the discomfort after several weeks.