Such low blood pressure is definitely a cause of concern.
Poor oral intake, excessive sweating, water loss from body by vomitings or loose motions , some infection in body might cause low BP.
But serious cause of low BP like heart problem etc should be ruled out.
Next Steps
Drink plenty of fluids coconut water Electrol powder, salted drink like lemon juice, butter milk might help.
take salted food items.
Health Tips
Please consult Physician in person for Physical check up and BP check and further work up ,if not better