Whether to be concerned us likely to be based on your economic knowledge or your gut. On the face of it, it is a very large number and is growing - your gut tells you it is wrong, it is unsustainable and harming the economy. What could we do with all that money we use to service debt? A common question usually put by politicians who want you to agree with austerity as a means to reduce the debt.
Since 2008, politicians have wanted you to believe that debt is bad and unless we pay it off quickly we are all doomed. There is only one way of reducing debt, spend less than you take in. Austerity or tax increases. Both have risks attached to them, both can suppress economic growth and both can be politically toxic. The Tories have managed to convince huge swathes of the electorate that austerity is a necessity, they haven't provided any alternatives and haven't explained why it is necessary other than "to reduce the debt". They are borrowing more than any other government but that is just an inconvenient truth so not mentioned.
For generations we have had debt, it has gone up and down at various times...sometimes by choice, sometimes by circumstances. The expectation that on the back of a global financial crash, widespread economic troubles and slow economic growth that we should do a complete about turn in our economic planning is farcical. And in the UK it hasn't worked, the brakes have been eased but the harm has been done. It may be decades before our economy returns to pre2008 levels.
So no, I think your concern is overstated.